Entering the 1938 campaign, the Democratic Party had elected three successive governors, Al Smith, Franklin D. Roosevelt and Herbert H. Lehman, continuously holding the office since 1918, with the exception of the two-year term of Republican Nathan Miller from 1921–23.

Lehman, who was first elected in 1932 had won three terms by landslide margins as the Great Depression badly damaged Republican support in New York and many urban centers throughout the United States.

One bright spot in the New York Republican Party was Thomas E. Dewey, a young Manhattan special prosecutor appointed by Lehman who had won national fame as a "gangbuster" for his successful arrests and prosecutions of organized crime figures, including Lucky Luciano and Lepke Buchalter.

[1] His 1938 prosecution of former New York Stock Exchange president Richard Whitney for embezzlement also won him the support of financial reformers, raising him to the status of authentic national hero.

[2] Dewey began laying the groundwork for a statewide campaign as early as summer 1936, when he met with Nassau County political boss J. Russell Sprague at the Long Island estate of Henry Root Stern, an attorney and treasurer of the state Republican Party.

Following Robert Moses's disastrous performance in the 1934 election, Sprague was one of a coterie of young Republican leaders who sought to reform the party, including Edwin Jaeckle of Buffalo, W. Kingsland Macy of Suffolk County, and Kenneth Simpson of Manhattan.

[3] In 1937, Samuel Seabury and other city reformers, including mayor Fiorello La Guardia and Adolf Berle, recruited Dewey to run for Manhattan District Attorney on a cross-party fusion ticket.

[7] His political fortunes suffered a setback in the summer when judge Ferdinand Pecora declared a mistrial in his prosecution of Tammany Hall leader James Joseph Hines, but the Republican Party remained solidly behind him.

Avoiding referencing Lehman, who had not yet agreed to run, by name, he charged, "any Democratic governor is, perforce, the good-will advertising, the front man, the window dressing for what is, in part at least, a thoroughly corrupt machine.

Seeking to gain independent and Democratic support, he openly referred to himself as a "New Deal Republican" and criticized Lehman as nothing more than "a branch manager in a chain store system of national politics.

Roosevelt advised an approach which conceded Dewey's evident popularity, urging, "The best line that can be circulated in upstate New York, especially among Republican or Independent voters, is 'I propose to vote for Dewey—to continue as District Attorney for the balance of his term.

'"[21] In a late effort to swing the large Jewish bloc in New York City, Roosevelt spoke obliquely of an anti-Semitic "whispering campaign", and Lehman seized on local Republican posters urging citizens to "Vote the American Way.

"[21] On November 4, two days before the election, Roosevelt publicly endorsed Lehman and launched his final attack, criticizing Dewey as "yet to win his spurs" and comparing "old-time Republicans" to fascists and communists as a threat to democracy.

Addressing the claim that he should be judged by his supporters, Dewey attacked the ties between the Democratic machine and organized crime, displaying a sheriff's commission given by Ed Flynn to mobster Dutch Schultz for the audience.