From March 9 to June 1, 1948, voters of the Republican Party elected delegates to the 1948 Republican National Convention, in part to choose the party nominee for president in the 1948 United States presidential election.

The 1948 Republican National Convention was held from June 21 to June 25, 1948, in Philadelphia, Pennsylvania. New York Governor Thomas E. Dewey was nominated for president and California Governor Earl Warren was nominated for vice president. Dewey and Warren went on to lose the general election to the Democratic Party's ticket of incumbent President Harry S. Truman and Kentucky senator Alben W. Barkley.

Candidates Both the Republican Party and the Democratic Party courted Dwight D. Eisenhower, the most popular United States general of World War II. Eisenhower's political views were unknown in 1948. He was, later events would prove, a moderate Republican, but in 1948 he flatly refused the nomination of any political party.

With Eisenhower refusing to run, the contest for the Republican nomination was between New York Governor Thomas E. Dewey, former Minnesota Governor Harold Stassen, General Douglas MacArthur, Ohio Senator Robert A. Taft and California Governor Earl Warren. Governor Dewey, who had been the Republican nominee in 1944, was regarded as the frontrunner when the primaries began. Dewey was the acknowledged leader of the GOP's powerful eastern establishment; in 1946 he had been re-elected Governor of New York by the largest margin in state history. Dewey's handicap was that many Republicans disliked him; he often struck observers as cold, stiff and condescending. Senator Taft was the leader of the GOP's conservative wing. He opened his campaign in 1947 by attacking the Democratic Party's domestic policy and foreign policy. In foreign policy, Taft was a non-interventionist who opposed many of the alliances the U.S. government had made with other nations to fight the Cold War with the Soviet Union; he believed that the nation should concentrate on its own problems and avoid "imperial entanglements". On domestic issues, Taft and his fellow conservatives wanted to abolish many of the New Deal social welfare programs that had been created in the 1930s; they regarded these programs as too expensive and harmful to business interests. Taft had two major weaknesses: he was seen as a plodding, dull campaigner, and he was viewed by most party leaders as being too conservative and controversial to win a presidential election. Taft's support was limited to his native Midwestern United States and parts of the Southern United States.

The "surprise" candidate of 1948 was Stassen, the former "boy wonder" of Minnesota politics. Stassen had been elected governor of Minnesota at the age of 31; he resigned as governor in 1943 and served in the United States Navy in World War II. In 1945 he had served on the committee which created the United Nations. Stassen was widely regarded as the most "liberal" of the Republican candidates, yet as the primaries continued he was criticized for being vague on many issues.

Nominee CandidateExperienceHome stateCampaignPopular voteContests wonRunning mateThomas E. DeweyGovernor of New York (1943–1954)

Manhattan District Attorney

(1938-1941)

Nominee for president in 1944New York(Campaign) Secured nomination: June 24, 1948330,799 (11.6%)2Earl Warren

Major candidates These candidates participated in multiple state primaries or were included in multiple major national polls.

Competing in primaries CandidateExperienceHome stateCampaignPopular voteContests wonDouglas MacArthurCommander of the Far East Command (1945–1951) Supreme Commander for the Allied Powers (1945–1951) Military Advisor to the Philippines(1935–1941)

Army Chief of Staff(1930–1935)New York(Campaign)Leverett SaltonstallU.S. Senatorfrom Massachusetts (1945–67) Governor of Massachusetts(1939–1945)Massachusetts(Campaign)Harold StassenGovernor of Minnesota(1939–1943)Minnesota(Campaign)Robert A. TaftU.S. Senatorfrom Ohio(1939–1953)OhioAnnounced campaign: October 24, 1947(Campaign)Arthur VandenbergU.S. Senator from Michigan(1928–1951)MichiganEarl WarrenGovernor of California(1943–53) Attorney General of California(1939-1943)

Chair of the California Republican Party(1932–1938)

District Attorney of Alameda County(1925-1939)

Candidate for president in 1936 and 1944California Bypassing primaries The following candidates did not actively campaign for any state's presidential primary, but may have had their name placed on the ballot by supporters or may have sought to influence to selection of un-elected delegates or sought the support of uncommitted delegates. CandidateExperienceHome stateRaymond BaldwinU.S. Senatorfrom Connecticut(1946–49)ConnecticutDwight H. GreenGovernorof Illinois(1941–49)IllinoisEdward MartinU.S. Senatorfrom Pennsylvania(1947–59)PennsylvaniaJoseph Martin Jr.Speaker of the House(1947–49)MassachusettsB. Carroll ReeceChairman of the RNC(1946–48)Tennessee

Favorite sons The following candidates ran only in their home state's primary or caucus for the purpose of controlling its delegate slate at the convention and did not appear to be considered national candidates by the media. Businessman Riley A. Bender of Illinois Newspaper publisher R.W. Hitchcock of South Dakota

Polling

National polling

SourcePublication GallupApril, 19458%59%–1%7%1%15%2%4%1%2%GallupJanuary, 19468%38%3%–6%2%27%4%4%1%6%GallupMarch, 194611%37%2%1%3%1%33%3%6%1%2%GallupApril, 194610%35%2%2%5%1%34%3%5%–3%GallupJuly, 19469%38%2%–6%–28%4%7%–6%GallupJuly, 19469%37%2%–4%1%25%5%8%6%3%GallupOctober, 19468%40%2%1%5%1%22%6%7%6%2%GallupNovember, 19468%52%2%–2%1%17%2%9%5%2%GallupFebruary, 19476%45%6%–3%–18%8%8%3%3%GallupApril, 19476%51%4%–2%–15%7%10%3%2%GallupJune, 19473%50%4%–3%–15%9%9%4%3%GallupJanuary, 1948–33%19%–10%–12%13%5%5%3%GallupMarch, 1948–37%––12%1%15%14%13%2%2%GallupMarch, 1948–34%––19%1%15%12%13%3%3%GallupApril, 1948–29%––16%–31%9%10%2%3%GallupApril, 1948–24%––12%–37%8%13%2%4%GallupJune, 1948–33%––11%–26%10%13%2%5% Source:

Primary campaign New Hampshire: March 9 Dewey declined to enter the campaign actively while the New York legislature remained in session. In New Hampshire, that meant Dewey relied on the state's Governor, Charles M. Dale, and other supporters to deliver the eight-person delegation to his column. His campaign spent only $9,000.

The result was inconclusive. Dewey took six of the state's eight delegates, and the most popular Dewey delegate outpolled the most popular Stassen delegate by 28,000 votes to 21,000.

Wisconsin: April 6 Wisconsin had proven decisive in 1944 by eliminating Wendell Willkie from the campaign after a poor showing; in 1948, it evolved into a contest between native son Douglas MacArthur and neighbor Harold Stassen of Minnesota. Dewey, maintaining his front-runner approach, remained in Albany and nearly declined to enter the primary, submitting his name only halfheartedly at the last minute.

The Stassen campaign benefited from the large Scandinavian population and the support of Senator Joseph McCarthy, while MacArthur, still in Tokyo, was supported by the La Follette family, the Milwaukee Sentinel, and many of Dewey's 1944 campaigners. McCarthy, a Catholic, criticized MacArthur for his remarriage and divorce; the attack was aimed at the state's large Catholic population. Stassen also succeeded by appealing to both young and liberal voters (through internationalist foreign policy) and conservative and ethnic voters (by calling for a national ban on the Communist Party). In an indirect attack on Dewey, he noted that forty percent of the nation's communists resided in New York.

Though he did not initially campaign in the state, Dewey was weakened by Wisconsin; the leading candidates and other enemies, like former Congressman Hamilton Fish III, had the opportunity to attack him while he remained in New York. Dewey briefly entered the fray in the final days, delivering speeches at Kenosha and Appleton College, and issuing a statewide radio broadcast on April 1 to criticize Stassen's proposed ban on communists, famously arguing, "You can't shoot an idea with a gun."

Stassen won a triumph over MacArthur, taking nineteen delegates to the General's eight. Dewey was shut out, though he captured ten delegates in Oklahoma.

Nebraska: April 13 One week after Wisconsin, Stassen again bested Dewey in Nebraska. Dewey had made a much stronger effort there, having left Wisconsin early to deliver a foreign policy speech in Lincoln. The two were joined on the campaign trail in Nebraska by Senator Robert A. Taft, entering his first primary. Given a break in the Senate schedule for Lincoln's birthday, Taft campaigned in Nebraska, as well as Indiana, Illinois, Minnesota, and Colorado in the span of one week.

Taft was unpopular in the state over his opposition to farm subsidies and unable to campaign until Senate business concluded; he likely preferred to bypass the state altogether. His hand was forced, however, by an independent committee which placed the names of all candidates on the ballot and Senator Hugh A. Butler, who offered Taft the support of his political organization and personally planned a three-day campaign trip for him; he reluctantly agreed. The result was disaster for Taft, who finished a distant third (with only twice the vote of the non-candidate Vandenberg) and a boost for Stassen, who won a clean victory over Dewey.

Now with clear momentum, Stassen appeared to be the favorite for the nomination; he led in the Gallup poll for the first time and was the betting favorite to win the crucial Oregon primary, his next showdown with Dewey. Faced with the definite prospect of a third failed presidential campaign, the press began to write Dewey off. "Although he is not a tragic figure," wrote the liberal magazine The Nation, "there is an element of tragedy in his collapse as a leading contender. ... [H]e has pursued such a cautious course and been so clearly motivated by ambition that he stands for nothing and has no real friends."

Dewey thus decided to stake his political career on Oregon and left for the state on April 20, to establish a campaign and barnstorm for votes.

Ohio: May 4 In January, Stassen made a serious violation of political etiquette by challenging a candidate in his home state. Though Taft personally appealed to Stassen to desist for both candidacies' sakes, the Minnesotan pressed forward with a January 25 announcement that he would controversially file in Ohio, angering Taft and his conservative supporters. Stassen reasoned that he must campaign in the state, since he relied entirely on popular support without establishment backing. After losing Nebraska, Taft hurried home, where he would campaign from April 17 until primary day, speaking eight to ten times per day.

Stassen focused his strength by running a slate of only twenty-three delegates out of a possible fifty-three. Only one, a respected former Ohio Supreme Court justice, ran at-large; the other twenty-two ran in carefully selected districts in the urban centers of Akron, Cleveland, Dayton, and Youngstown. Stassen presumed that voters in these districts would oppose Taft for his sponsorship of the anti-union Taft-Hartley Act.

Taft ridiculed Stassen for vagueness on the issues and took a firm stance in response against universal military training. He proudly spoke in favor of Taft-Hartley and also noted his public housing and education aid bills. Taft's public relations advisor L. Richard Guylay utilized a radio campaign based on the principles of Gustave Le Bon, targeting veterans, young voters, and even union members with a direct appeal to emotion.