So You Say You Want an Evolution? Generational v. Ideological Decline within Republican Noninterventionism

During research for “Partisans of the Old Republic: Right-Wing Opposition to U.S. Foreign Policy, 1934-1992,” I have been vexed by one question more than any other: how much of the decline of “isolationism” can be attributed to individuals flipping from noninterventionism, versus a more extensive, generational evolution within the American right. I have been searching for a computational way to approach this problem for months.

Current scholarship on the decline of interventionism within the Republican party focuses on the importance of events. Political historians and national security scholars often cite the impact of World War II and Korea as being the combined death knells of the Old Right and their noninterventionist tendencies.

This thesis is supported by a deluge of Republicans who saw the light after World War II or the Korean War. The combination of a power vacuum left by the weakening of the British Empire coupled with the threat of the Soviet Union caused these holdouts to give up their noninterventionist tendencies in the name of fighting communism. The abrupt turn of Senator Arthur Vandenberg after WWII is a prime example of an individual evolution serving the impetus for the transformation of the GOP. The career of Rep. Robert Chiperfield is indicative of this trend within the House of Representatives after he flipped upon the start of the Korean War. A young Gerald Ford, then a Yale law student, was a founding member of the America First Committee. Hell, even Barry Goldwater opposed U.S. government policy in French Indochina during his first stint in the U.S. Senate (believe it or not).

Despite such examples, the explanation of individual evolution has seemed lacking. I have been pouring (often obsessing) over this data for two years now, and there seem to be enough loose ends to challenge the importance of this thesis. How can I put it to the test using my dataset?

I may have stumbled upon a solution.

I decided to use the voting records that I have compiled thus far to determine how many congressional members manifested a noticeable decline in their opposition throughout their careers. Since I am looking for broader trends, I decided to limit my search to Representatives and Senators who served at least four congresses (eight years). Such a span would be more likely to cover a comprehensive array of events, presidential administration, wars, and changes into congressional governance. This sample will likely serve as a reliable proxy for the party as a whole.

Name	Starting Opposition Mean	Ending Opposition Mean	Change	Wing of Party	Region	Generation
ADAIR, Edwin Ross	0.519230769230769	0.336369770580297	0.182860998650472	Center	Midwest	greatest
AIKEN, George David	0.580227743271222	0.223141598825571	0.357086144445651	Center	North	lost
ALLEN, Leo Elwood	0.746212121212121	0.460714285714286	0.285497835497835	Center	Midwest	lost
ANDERSEN, Herman Carl	0.684027777777778	0.503968253968254	0.180059523809524	Right	Midwest	lost
ANDERSON, John Bayard	0.566666666666667	0.29983660130719	0.266830065359477	Center	Midwest	greatest
ANDRESEN, August Herman	0.825757575757576	0.496969696969697	0.328787878787879	Right	Midwest	lost
ANDREWS, Walter Gresham	0.781746031746032	0.0952380952380952	0.686507936507937	Center	North	lost
ARENDS, Leslie Cornelius	0.757692307692308	0.0904095904095904	0.667282717282717	Center	Midwest	lost
ASHBROOK, John Milan	0.647009966777409	0.395748855461086	0.251261111316323	Right	Midwest	silent
BATES, George Joseph	0.615056818181818	0.191666666666667	0.423390151515151	Center	North	lost
BATTIN, James Franklin	0.519642857142857	0.525641025641026	-0.00599816849816848	Right	Rockies	greatest
BEAMER, John Valentine	0.519230769230769	0.522727272727273	-0.00349650349650354	Center	Midwest	lost
BENDER, George Harrison	0.525	0.0839160839160839	0.441083916083916	Center	Midwest	lost
BLACKNEY, William Wallace	0.654545454545455	0.393939393939394	0.260606060606061	Center	Midwest	missionary
BRADLEY, Frederick Van Ness	0.639194139194139	0.916666666666667	-0.277472527472528	Center	Midwest	lost
BREWSTER, Ralph Owen	0.846153846153846	0.422857142857143	0.423296703296703	Center	North	lost
BRICKER, John William	0.536062378167641	0.457516339869281	0.0785460382983603	Right	Midwest	lost
BROCK, William Emerson, III	0.507440476190476	0.198234155781326	0.309206320409151	Center	South	silent
BROOKS, Charles Wayland	0.6	0.597953216374269	0.00204678362573096	Center	Midwest	lost
BROWN, Clarence J.	0.578214578214578	0.553571428571429	0.0246431496431496	Center	Midwest	lost
BROYHILL, James Thomas	0.524193548387097	0.271634615384615	0.252558933002481	Right	South	greatest
BUDGE, Hamer Harold	0.557692307692308	0.568103448275862	-0.0104111405835543	Right	Rockies	greatest
BUFFETT, Howard Homan	0.516624040920716	0.741666666666667	-0.225042625745951	Right	Midwest	greatest
BURDICK, Usher Lloyd	0.742424242424242	0.576190476190476	0.166233766233766	Left	Midwest	missionary
BURTON, Laurence Junior	0.507211538461538	0.381756756756757	0.125454781704782	Right	Rockies	greatest
BUTLER, Hugh Alfred	0.638211382113821	0.641025641025641	-0.00281425891181986	Right	Midwest	missionary
CAPEHART, Homer Earl	0.553571428571429	0.467908902691511	0.0856625258799172	Center	Midwest	lost
CAPPER, Arthur	0.870588235294118	0.359649122807018	0.5109391124871	Right	Midwest	missionary
CARLSON, Frank	0.958333333333333	0.193627450980392	0.764705882352941	Center	Midwest	lost
CARTER, Albert Edward	0.527272727272727	0.3	0.227272727272727	Center	West	missionary
CASE, Francis Higbee	0.85	0.450828157349896	0.399171842650104	Right	Midwest	lost
CHIPERFIELD, Robert Bruce	0.616287878787879	0.0540540540540541	0.562233824733825	Center	Midwest	lost
CHURCH, Ralph Edwin	0.742424242424242	0.875	-0.132575757575758	Center	Midwest	lost
CLANCY, Donald Daniel	0.510569105691057	0.457983834070459	0.0525852716205978	Center	Midwest	greatest
CLASON, Charles Russell	0.693181818181818	0.0833333333333333	0.609848484848485	Center	North	lost
CLAUSEN, Donald Holst	0.535555555555556	0.293956795187312	0.241598760368244	Right	West	greatest
CLAWSON, Delwin Morgan	0.581730769230769	0.430319333564734	0.151411435666035	Right	West	greatest
CLEVENGER, Cliff	0.625	0.557692307692308	0.0673076923076923	Right	Midwest	lost
COLE, William Sterling	0.773504273504274	0.136363636363636	0.637140637140637	Center	North	greatest
COLLIER, Harold Reginald	0.582010582010582	0.313218390804598	0.268792191205984	Center	Midwest	greatest
CORBETT, Robert James	0.529185867895545	0.13452380952381	0.394662058371736	Center	North	greatest
CORDON, Guy	0.522727272727273	0.340909090909091	0.181818181818182	Right	West	lost
CRAWFORD, Fred Lewis	0.875	0.666666666666667	0.208333333333333	Right	Midwest	lost
CULKIN, Francis Dugan	0.9	0.166666666666667	0.733333333333333	Center	North	missionary
CUNNINGHAM, Glenn Clarence	0.5503663003663	0.33531746031746	0.21504884004884	Center	Midwest	greatest
CURTIS, Carl Thomas	0.644230769230769	0.328048780487805	0.316181988742964	Center	Midwest	greatest
DAVIS, James John	0.645833333333333	0.472838137472284	0.172995195861049	Right	North	missionary
DERWINSKI, Edward Joseph	0.578289473684211	0.209869333527995	0.368420140156216	Center	Midwest	greatest
DEVINE, Samuel Leeper	0.610714285714286	0.422822937968644	0.187891347745642	Right	Midwest	greatest
DICKINSON, William Louis	0.611695906432749	0.282668881506091	0.329027024926658	Center	South	greatest
DIRKSEN, Everett McKinley	0.622727272727273	0.195024077046549	0.427703195680724	Center	Midwest	lost
DITTER, John William	0.696969696969697	0.271428571428571	0.425541125541126	Center	North	lost
DOLE, Robert Joseph	0.564891222805701	0.165378464818763	0.399512757986938	Center	Midwest	greatest
DONDERO, George Anthony	0.763636363636364	0.406593406593407	0.357042957042957	Center	Midwest	lost
DOUGLAS, Fred James	0.792338709677419	0.19047619047619	0.601862519201229	Center	North	missionary
DUNCAN, John James	0.566106804478897	0.195652173913043	0.370454630565854	Right	South	greatest
DWORSHAK, Henry Clarence	0.601136363636364	0.666666666666667	-0.0655303030303032	Right	Rockies	lost
EATON, Charles Aubrey	0.738636363636364	0.0625	0.676136363636364	Center	North	missionary
EDWARDS, William Jackson (Jack)	0.515350877192982	0.18055152394775	0.334799353245232	Right	South	silent
ELSTON, Charles Henry	0.577323717948718	0.514285714285714	0.0630380036630037	Center	Midwest	lost
ENGEL, Albert Joseph	0.821969696969697	0.166666666666667	0.65530303030303	Center	Midwest	lost
FISH, Hamilton	0.714285714285714	0.236363636363636	0.477922077922078	Center	North	lost
GEORGE, Myron Virgil	0.791666666666667	0.253105590062112	0.538561076604555	Center	Midwest	lost
GIFFORD, Charles Laceille	0.738888888888889	0.65	0.0888888888888889	Center	North	missionary
GILCHRIST, Fred Cramer	0.821428571428571	0.29375	0.527678571428571	Right	Midwest	missionary
GILLIE, George W.	0.556743421052632	0.608333333333333	-0.0515899122807018	Center	Midwest	missionary
GOLDWATER, Barry Morris	0.716970998925886	0.132343611216851	0.584627387709035	Right	Southwest	greatest
GRAHAM, Louis Edward	0.533333333333333	0.291666666666667	0.241666666666667	Center	North	missionary
GRANT, Robert Allen	0.581597222222222	0.456845238095238	0.124751984126984	Center	Midwest	greatest
GROSS, Harold Royce	0.717948717948718	0.675249169435216	0.042699548513502	Right	Midwest	lost
GURNEY, Edward John	0.590659340659341	0.211289092295957	0.379370248363383	Right	South	greatest
GUYER, Ulysses Samuel	0.883116883116883	0.330128205128205	0.552988677988678	Right	Midwest	missionary
GWYNNE, John Williams	0.787878787878788	0.571428571428571	0.216450216450216	Right	Midwest	lost
HALL, Durward Gorham	0.607657657657658	0.450500770416025	0.157156887241633	Right	Midwest	greatest
HALLECK, Charles Abraham	0.734615384615385	0.2618825722274	0.472732812387985	Center	Midwest	lost
HANCOCK, Clarence Eugene	0.651515151515151	0.155263157894737	0.496251993620415	Center	North	lost
HANSEN, George Vernon	0.544444444444444	0.341801928957892	0.202642515486552	Right	Rockies	silent
HARDEN, Cecil Murray	0.518181818181818	0.171264367816092	0.346917450365726	Center	Midwest	lost
HARNESS, Forest Arthur	0.627467105263158	0.650724637681159	-0.0232575324180015	Center	Midwest	lost
HARRISON, Robert Dinsmore	0.644230769230769	0.464285714285714	0.179945054945055	Right	Midwest	lost
HARRISON, William Henry	0.541958041958042	0.51778329197684	0.0241747499812015	Right	Rockies	lost
HARSHA, William Howard	0.529824561403509	0.451813922032752	0.0780106393707567	Right	Midwest	greatest
HARTLEY, Fred Allan, Jr.	0.577777777777778	0.302631578947368	0.275146198830409	Center	North	greatest
HESS, William Emil	0.681818181818182	0.12962962962963	0.552188552188552	Center	Midwest	lost
HOFFMAN, Clare Eugene	0.809090909090909	0.766666666666667	0.0424242424242425	Right	Midwest	missionary
HOFFMAN, Richard William	0.693181818181818	0.558441558441558	0.13474025974026	Center	Midwest	lost
HOPE, Clifford Ragsdale	0.884615384615385	0	0.884615384615385	Right	Midwest	lost
HRUSKA, Roman Lee	0.538461538461538	0.179924242424242	0.358537296037296	Center	Midwest	greatest
HULL, Merlin	0.866666666666667	0.748251748251748	0.118414918414918	Left	Midwest	missionary
HUTCHINSON, J. Edward	0.545039561777237	0.482936507936508	0.0621030538407288	Center	Midwest	greatest
JENKINS, Thomas Albert	0.755244755244755	0.293939393939394	0.461305361305361	Center	Midwest	missionary
JENNER, William Ezra	0.586666666666667	0.847222222222222	-0.260555555555556	Right	Midwest	greatest
JENSEN, Benton Franklin	0.576190476190476	0.59047619047619	-0.0142857142857143	Right	Midwest	lost
JOHANSEN, August Edgar	0.517857142857143	0.647465437788018	-0.129608294930876	Right	Midwest	greatest
JOHNSON, Anton Joseph	0.65034965034965	0.776785714285714	-0.126436063936064	Right	Midwest	missionary
JOHNSON, James Paul (Jim)	0.521312260536398	0.534666666666667	-0.0133544061302682	Center	Rockies	silent
JOHNSON, Noble Jacob	0.632560483870968	0.58421052631579	0.0483499575551782	Center	Midwest	lost
JONES, Robert Franklin	0.625	0.816666666666667	-0.191666666666667	Right	Midwest	greatest
JONKMAN, Bartel John	0.615441176470588	0.311141304347826	0.304299872122762	Center	Midwest	lost
JORDAN, Leonard Beck (Len)	0.774898785425101	0.270088618938564	0.504810166486537	Center	Rockies	lost
KEARNS, Carroll Dudley	0.516666666666667	0.171052631578947	0.345614035087719	Center	North	lost
KEEFE, Frank Bateman	0.586111111111111	0.5	0.086111111111111	Center	Midwest	lost
KINZER, John Roland	0.742424242424242	0.361111111111111	0.381313131313131	Center	North	missionary
KNUTSON, Harold	0.866666666666667	0.821969696969697	0.0446969696969697	Right	Midwest	missionary
LAMBERTSON, William Purnell	0.829545454545455	0.678498985801217	0.151046468744238	Right	Midwest	missionary
LANDIS, Gerald Wayne	0.596217105263158	0.565340909090909	0.0308761961722488	Center	Midwest	lost
LANGER, William	0.667953667953668	0.621328224776501	0.0466254431771673	Right	Midwest	lost
LEMKE, William	0.787878787878788	0.785714285714286	0.00216450216450215	Center	Midwest	missionary
LEWIS, Earl Ramage	0.515151515151515	0.392045454545455	0.123106060606061	Center	Midwest	lost
LODGE, Henry Cabot, Jr.	0.527868852459016	0.0497685185185185	0.478100333940498	Center	North	greatest
MAAS, Melvin Joseph	0.566666666666667	0.356481481481482	0.210185185185185	Center	Midwest	lost
MALONE, George Wilson	0.72	0.75233918128655	-0.0323391812865497	Right	Rockies	lost
MARTIN, David Thomas	0.556261343012704	0.325381879054195	0.230879463958509	Right	Midwest	greatest
MARTIN, Joseph William, Jr.	0.755555555555556	0.143939393939394	0.611616161616162	Center	North	lost
MARTIN, Thomas Ellsworth	0.51555023923445	0.154858299595142	0.360691939639308	Center	Midwest	lost
MASON, Noah Morgan	0.757142857142857	0.804812834224599	-0.0476699770817418	Right	Midwest	missionary
McCULLOCH, William Moore	0.563636363636364	0.170230263157895	0.393406100478469	Center	Midwest	greatest
McLEAN, Donald Holman	0.646153846153846	0.194594594594595	0.451559251559251	Center	North	lost
McNARY, Charles Linza	0.583333333333333	0.5	0.0833333333333333	Right	West	missionary
McVEY, William Estus	0.606060606060606	0.584045584045584	0.0220150220150219	Center	Midwest	lost
MICHEL, Robert Henry	0.609962406015038	0.145959595959596	0.464002810055442	Center	Midwest	greatest
MICHENER, Earl Cory	0.821212121212121	0.177884615384615	0.643327505827506	Center	Midwest	missionary
MILLER, Jack Richard	0.554945054945055	0.197302923341479	0.357642131603576	Center	Midwest	greatest
MOORE, Arch Alfred, Jr.	0.544973544973545	0.465023847376789	0.0799496975967563	Center	South	greatest
MORSE, Wayne Lyman	0.526315789473684	0.176470588235294	0.34984520123839	Left	West	lost
MOTT, James Wheaton	0.55	0.0277777777777778	0.522222222222222	Center	West	lost
MUNDT, Karl Earl	0.530681818181818	0.158708414872798	0.37197340330902	Center	Midwest	lost
MURRAY, Reid Fred	0.674242424242424	0.541666666666667	0.132575757575758	Center	Midwest	lost
NELSON, Charles Pembroke	0.555555555555556	0.477272727272727	0.0782828282828283	Center	North	greatest
NYE, Gerald Prentice	0.888888888888889	0.584345479082321	0.304543409806568	Right	Midwest	lost
O'KONSKI, Alvin Edward	0.596491228070175	0.501754385964912	0.0947368421052631	Right	Midwest	greatest
OSMERS, Frank Charles, Jr.	0.645104895104895	0.0536130536130536	0.591491841491842	Center	North	greatest
PAUL, Ronald Ernest	0.73579418344519	0.721784663320062	0.0140095201251278	Right	Southwest	silent
PITTENGER, William Alvin	0.56969696969697	0.398947368421053	0.170749601275917	Center	Midwest	lost
PLUMLEY, Charles Albert	0.696969696969697	0.362637362637363	0.334332334332334	Center	North	missionary
POWERS, David Lane	0.73030303030303	0.142156862745098	0.588146167557932	Center	North	lost
PRESSLER, Larry Lee	0.531540797335684	0.235407782515991	0.296133014819693	Center	Midwest	silent
QUILLEN, James Henry	0.573333333333333	0.286630036630037	0.286703296703297	Right	South	greatest
REECE, Brazilla Carroll	0.631818181818182	0.399470899470899	0.232347282347282	Right	South	lost
REED, Chauncey William	0.709090909090909	0.5	0.209090909090909	Center	Midwest	lost
REED, Clyde Martin	0.724916943521595	0.140522875816993	0.584394067704601	Right	Midwest	missionary
REED, Daniel Alden	0.75	0.485119047619048	0.264880952380952	Right	North	missionary
REES, Edward Herbert	0.878787878787879	0.441379310344828	0.437408568443051	Center	Midwest	lost
REID, Charlotte Thompson	0.5815649867374	0.2324016563147	0.349163330422701	Center	Midwest	greatest
REVERCOMB, William Chapman	0.735645933014354	0.533549783549784	0.202096149464571	Right	South	lost
RICH, Robert Fleming	0.958333333333333	0.837662337662338	0.120670995670996	Right	North	lost
ROBSION, John Marshall	0.716783216783217	0.741071428571429	-0.0242882117882117	Right	South	missionary
RODGERS, Robert Lewis	0.51008064516129	0.319548872180451	0.190531772980839	Center	North	missionary
ROUDEBUSH, Richard Lowell	0.558284457478006	0.395089285714286	0.16319517176372	Right	Midwest	greatest
ROUSSELOT, John Harbin	0.655677655677656	0.353643724696356	0.302033930981299	Right	West	greatest
SCHADEBERG, Henry Carl	0.615222876366695	0.440587867417136	0.174635008949559	Center	Midwest	greatest
SCHERLE, William Joseph	0.506678281068525	0.475033738191633	0.0316445428768921	Right	Midwest	greatest
SCHOEPPEL, Andrew Frank	0.662352941176471	0.59375	0.0686029411764706	Right	Midwest	lost
SCRIVNER, Errett Power	0.613333333333333	0.467592592592593	0.145740740740741	Center	Midwest	lost
SHAFER, Paul Werntz	0.861538461538462	0.583333333333333	0.278205128205128	Center	Midwest	lost
SHEEHAN, Timothy Patrick	0.618181818181818	0.576923076923077	0.0412587412587413	Center	Midwest	greatest
SHIPSTEAD, Henrik	0.833333333333333	0.848684210526316	-0.0153508771929824	Right	Midwest	missionary
SHORT, Dewey Jackson	0.696969696969697	0.5	0.196969696969697	Right	Midwest	lost
SHUSTER, E. G. (Bud)	0.565978573295009	0.294799054373522	0.271179518921487	Right	North	silent
SILER, Eugene	0.58	0.634848484848485	-0.0548484848484847	Right	South	lost
SIMPSON, Richard Murray	0.65	0.203333333333333	0.446666666666667	Center	North	lost
SKUBITZ, Joe	0.509453781512605	0.363830858293481	0.145622923219124	Right	Midwest	greatest
SMITH, Frederick Cleveland	0.684090909090909	0.964285714285714	-0.280194805194805	Right	Midwest	lost
SMITH, H. Allen	0.595238095238095	0.34219001610306	0.253048079135036	Right	West	greatest
SMITH, Wint	0.783333333333333	0.645833333333333	0.1375	Right	Midwest	lost
SNYDER, Marion Gene	0.59072249589491	0.319601677148847	0.271120818746063	Right	South	silent
SPRINGER, Raymond Smiley	0.593939393939394	0.7	-0.106060606060606	Center	Midwest	missionary
STEFAN, Karl	0.923076923076923	0.596153846153846	0.326923076923077	Right	Midwest	lost
SUMNER, Jessie	0.663636363636364	0.696524064171123	-0.0328877005347594	Right	Midwest	lost
SYMMS, Steven Douglas	0.581144465290807	0.19786581113126	0.383278654159547	Right	Rockies	silent
TABER, John	0.67948717948718	0.417582417582418	0.261904761904762	Right	North	missionary
TAFT, Robert Alphonso	0.633684621389539	0.176470588235294	0.457214033154245	Center	Midwest	lost
TALLE, Henry Oscar	0.53125	0.437037037037037	0.094212962962963	Center	Midwest	lost
TAYLOR, Gene	0.515664160401002	0.230152161456675	0.285511998944327	Right	Midwest	silent
THOMAS, John	0.695394736842105	0.59375	0.101644736842105	Right	Rockies	missionary
THOMAS, John Parnell	0.631493506493507	0.233766233766234	0.397727272727273	Center	North	lost
THOMSON, Vernon Wallace	0.533333333333333	0.177145612343298	0.356187720990035	Center	Midwest	greatest
TIBBOTT, Harve	0.525675675675676	0.31547619047619	0.210199485199485	Center	North	lost
TOBEY, Charles William	0.95	0.5	0.45	Center	North	missionary
TOWER, John Goodwin	0.7734375	0.112903225806452	0.660534274193548	Center	Southwest	greatest
TREADWAY, Allen Towner	0.701388888888889	0.222222222222222	0.479166666666667	Center	North	missionary
UTT, James Boyd	0.516666666666667	0.55	-0.0333333333333334	Right	West	lost
VAN PELT, William Kaiser	0.613095238095238	0.636904761904762	-0.0238095238095237	Right	Midwest	greatest
VAN ZANDT, James Edward	0.504385964912281	0.0481997677119628	0.456186197200318	Center	North	lost
VANDENBERG, Arthur Hendrick	0.678571428571429	0.025	0.653571428571429	Center	Midwest	lost
VELDE, Harold Himmel	0.625874125874126	0.310606060606061	0.315268065268065	Center	Midwest	greatest
VORYS, John Martin	0.551282051282051	0.131054131054131	0.42022792022792	Center	Midwest	lost
VURSELL, Charles Wesley	0.518382352941176	0.10989010989011	0.408492243051067	Center	Midwest	missionary
WEAVER, Phillip Hart	0.516483516483516	0.434210526315789	0.0822729901677269	Right	Midwest	greatest
WHERRY, Kenneth Spicer	0.82516339869281	0.69047619047619	0.13468720821662	Right	Midwest	lost
WIGGLESWORTH, Richard Bowditch	0.503246753246753	0.0714285714285714	0.431818181818182	Center	North	lost
WILEY, Alexander	0.725396825396825	0.106671554252199	0.618725271144626	Center	Midwest	lost
WILLIAMS, John James	0.704678362573099	0.428599425137183	0.276078937435916	Right	South	greatest
WINTER, Thomas Daniel	0.623563218390805	0.548701298701299	0.074861919689506	Right	Midwest	lost
WITHROW, Gardner Robert	0.723776223776224	0.574712643678161	0.149063580098063	Center	Midwest	lost
WOLCOTT, Jesse Paine	0.733333333333333	0.196428571428571	0.536904761904762	Center	Midwest	lost
WOLFENDEN, James	0.818181818181818	0.329044117647059	0.489137700534759	Center	North	lost
WOLVERTON, Charles Anderson	0.531818181818182	0.129166666666667	0.402651515151515	Center	North	missionary
WOODRUFF, Roy Orchard	0.691666666666667	0.646153846153846	0.0455128205128206	Right	Midwest	missionary
WYMAN, Louis Crosby	0.500384024577573	0.296232876712329	0.204151147865244	Center	North	greatest

I then took the oppositional average of each member’s first two and last two congresses. 200 Republican Representatives or Senators met the threshold, having served at least eight congresses and averaged an opposition to U.S. foreign policy above 50% during the start of their careers. Of those 200, 132 of them finished their careers (last two congresses) with an opposition percentage below 50%.

However, looking at our members’ generational and ideological components makes for a more complicated picture. There is a strong trend toward political centrism among those that evolved into interventionism. Of those 132 who “flipped,” 91 were within the party’s moderate core. A mere 40 who turned into interventionists could be considered on the party’s right flank.

There also appears to be have been a robust generational component at play. Members of the Greatest and Silent generations seem to be over-represented among those right-of-center Republicans who started their careers as noninterventionists but drifted into interventionism.

Plotting these members over time makes the evolution more apparent. Younger right-wing Republicans were considerably more likely to end their careers as interventionists despite beginning as noninterventionists.

Older right-wing noninterventionists largely stayed the course despite the events of the Cold War. Their attitudes appeared less prone to change due to the course of events or the presence of a Republican in the White House (Nixon or Eisenhower). Right-wing noninterventionists of the Missionary or Lost generations were over twice as likely to end their congressional careers as they started them, opposed to U.S. foreign policy. Nineteen of those members increased their opposition throughout their careers (as opposed to only seven centrists). Even among those that did moderate themselves, most did not finish far below the 50% threshold.

Conversely, centrist Republicans evolved in their foreign policy thinking considerably earlier, either during or due to World War II and the Korean War. The thesis that holds that the GOP turned towards interventionism only holds true for the party’s moderate core.

However, the Republican right essentially held on to its noninterventionist worldview despite the occurrences of early the Cold War. The right flank of the GOP would not fully convert into interventionism until a new generation of conservatives took office.

The New Right’s early opposition to U.S. foreign policy was a mirage and was less rooted in principle than the “isolationism” of the Old Right. During the height of the Vietnam War, Republican opposition to U.S. foreign policy was often purely partisan. Members in the House and the Senate would often rationalize their desire to cut foreign aid and other programs because of the cost of fighting in Southeast Asia. There was also a desire among Republicans to obstruct the Johnson administration. For many Republicans, the military’s failure in Vietnam could be laid at the door of the White House. As such, the right’s generalized opposition to American foreign policy was a redirected frustration with the Vietnam War.

This contextual opposition is manifested in their voting records. There is a noticeable gap between the Republican party’s total foreign policy opposition v. their final vote opposition on the eve of the Vietnam War and through its escalation. Many Republicans would vote to cut funding or otherwise limit programs during floor amendments while ultimately voting “yay” on the final rollcall vote.

While such limited opposition was not new to the Vietnam era, its escalation suggests that GOP’s opposition to foreign policy became more political and less principled as a new generation of Republicans took office. Right-wing Republicans of the Missionary and Lost generations were considerably more likely to vote on principle and politics. Their opposition remained high throughout the early Cold War despite events and a Republican in the White House (Eisenhower, 1953-1961).

This gap between principled and political opposition manifested itself on the campaign trail as well. In 1968, retired Republican representative Eugene Siler (K.Y.) decided to run for an open Senate seat vacated by Thurston Morton. Siler was the only dissenting vote within the U.S. House on the Gulf of Tonkin Resolution. Additionally, Siler opposed the legislative precursors explicitly mentioned in that resolution. He voted against the delegation of authority to the president to defend the Republic of China’s redoubt on the island of Formosa (Taiwan), one of only three representatives to vote no. He also opposed the Eisenhower Doctrine, which expanded the U.S. government’s footprint within the Middle East and delegated to the president the authority to use military force in the region. Siler is the only Representative to oppose all three. In addition to these landmarks, he consistently voted against measures that unilaterally vested power in the executive branch to make foreign policy decisions and opposed most U.S. foreign aid programs.

When Siler formerly accounted for his candidacy he led with a policy on Vietnam that called for a gradual withdrawal of all U.S. forces from the conflict. Siler also used his announcement to take shots at his assumed rivals, many of whom had become newfound opponents of the war. He quipped that “another ahead-of-my-time viewpoint I have maintained for several years is that we ought to be waging peace instead of war,” and added, “I never believed we should fight any wars except defensive ones.” After a winnowing of the field, the primary came down to Eugene Siler and lawyer Marlow Cook.

The juxtaposition between these two men was symbolic of the ideological, cultural, and generational divisions within the Republican Party. Cook (born, 1926), a former state legislator, was a transplant from upstate New York and resident of Kentucky’s largest city, Louisville. Siler was a native-born Kentuckian (1900) and a self-described hillbilly. Cook was Catholic, Siler was Protestant. The localities that these men represented were more than mere geographical regions but embodied the two power bases of the Kentucky GOP, one static and the other ascendant. Siler’s rural 5^th district had for decades constituted the party’s predominant source of votes in statewide elections and had continuously sent a Republican representative to Washington for over 30 years. Cook’s Jefferson County (which contained Louisville) was one of the many growing suburban hubs of the Republican party and its New Right coalition.

Siler’s platform reflected the growing rift between the party’s two wings. Despite Siler’s opposition to Vietnam, his political views were outside the mainstream, even in a conservative state such as Kentucky. In addition to his opposition to war and foreign aid, Siler supported a balanced budget without caveats and advocated for the withdrawal of all U.S. forces stationed in Europe. Campaign watchers also considered Siler’s social and religious conservatism a political handicap. He was a proud teetotaler (a liability in a state known for its Bourbon), personally opposed divorce, and supported religious instruction in public schools. Cook lacked some of the conservative baggage exhibited by Siler but also dissented on the war in Vietnam (albeit for political reasons). Cook was initially noncommitted to the conflict. During an early debate between the two candidates, Siler declared the conflict “immoral and unconstitutional,” and Cook declined to comment due to ongoing negotiations.

Cook made his position clear as the campaign wore on, but it contrasted significantly to Siler’s. Like the outgoing Thurston Morton, he couched his opposition in the language of political frustration with the Johnson administration and its prosecution of the war. By May 1968, he advocated for withdrawal because the United States could not win “a war conducted by the State Department and Executive Branch.” If the military isn’t going to be allowed to win, “he declared, “we ought to get out.“

Cook’s position was roughly corresponded to what the American which had grown weary of the war by 1968, as its cost in American blood and treasure mounted. Cook’s moderate domestic positions, coupled with a mainstream opposition to the war, meant that he courted a more comprehensive array of voters. His positions negated any political advantage that Siler might have from his antiwar stance.

As a result, Siler was soundly defeated by Marlow Cook on Tuesday, 28 May 1968. After spending 13 times as much on his campaign, Marlow Cook earned almost twice the votes. A lack of institutional party support further hamstrung Siler. Initial postmortems of his campaign from voters and local political commentators cited his age, conservatism, localism, and “peculiar brand of isolationism” as reasons for his defeat. Cook would beat his Democratic opponent, Katherine Peden, in the general election. From the 91st until 93rd Congresses, Cook posted a mere 32% opposition to U.S. foreign policy.

The divisiveness of the war in Vietnam and its association with the Johnson administration allowed moderates like Morton to assail the war without questioning its underlying assumptions, along with the political programs which preceded it. Meanwhile, Siler, who opposed the war from the start based on long-standing principles, was undercut and politically hamstrung by his conservative worldview.

A similar phenomenon occurred within the Democratic party. Elite members of the liberal establishment and the Democratic party argued that the failure of Vietnam ought not to be used to question the entirety of the American postwar empire and undermine “the cherished lessons of the thirties, [and] the war years.” In both parties, the Overton Window was narrowed, and the lessons of Vietnam were firmly attenuated into the realms of strategy or tactics, not moralism or constitutionality.

If we fast forward to those who entered office after the Vietnam War, we can see the generational transformation of the Republican party continued until right-wing noninterventionism was (almost) completely extinguished. Of the 349 Republicans from the Silent and Boomer generations who started their careers after the 90^th Congress (1967-1969), only seven would post an opposition percentage above 50%. And, of them, none were Boomers, and only one of them, Ron Paul (Silent generation, born 1935), would serve into and beyond the Reagan era. During the Second Cold War, on the issue of foreign policy, younger Republicans voted more like Old Left Democrats than their conservative forebears.

Rank	Party	Generation	Opposition %	Number	Avg. Birth Year	% of Body
1	Republican	boomer	0.2543254	64	1949.766	0.03166749
2	Republican	silent	0.2783259	261	1936.126	0.12914399
3	Republican	greatest	0.2806877	93	1921.280	0.04601682
4	Democrat	boomer	0.3817476	77	1949.182	0.03809995
5	Democrat	greatest	0.3879735	124	1921.815	0.06135576
6	Democrat	silent	0.3962747	313	1937.294	0.1548738

So, what the hell happened? How is it that the center of the GOP was much more inclined to moderate itself due to the course of world events, while the Republican right was considerably less likely to do so? And why did it only transform after Vietnam?

Furthermore, why did it take a full generation for the Republican right to transform into interventionism, and why wasn’t the Old Right’s noninterventionism transmitted into later generations of conservatives?

I have a couple of hypotheses. First, is the “gatekeeping” function performed by conservative intellectuals like National Review’s William F. Buckley. Buckley exiled out of the conservative movement “ultra-right” figures like the John Birch Society, antiwar libertarians like Murray Rothbard, and radical individualists like Ayn Rand. Despite the flaws of these individuals, they all held on various heterodox (and prescient) ideas about the role of the U.S. in the world. The result of these purges was likely the expulsion of noninterventionism from the political and intellectual machinery of the emerging conservative movement.

A similar explanation may also lie with the machinations of Democratic presidents and regulatory agencies of the U.S. government. During the 1960s, the Federal Communications Commission used the politically motivated and selective enforcement of the Fairness Doctrine to undermine the first generation of conservative talk radio. Many of these radio commentators, like the controversial Dan Smoot, held on to deeply rooted noninterventionist ideas about foreign policy (despite their staunch anti-communism). The Internal Revenue Service also got in on the act and initiated politically motivated audits at the behest of President John F. Kennedy.

The combination of these purges and censorship, paired with the nationalization of the party politics, broke chains of transmission of noninterventionism within the political culture of the Republican right…or so goes my theory. Either way, the transformation of the Republican party was not merely a response to events but a long-term evolution of political culture between generations of political actors.

The goal now, for the sake of the dissertation, is to discover why…and how did these noninterventionist ideas survive their political exile.