Robert Alphonso Taft Sr. was an American politician, lawyer, and scion of the Republican Party's Taft family. Taft represented Ohio in the United States Senate, briefly served as Senate Majority Leader, and was a leader of the conservative coalition of Republicans and conservative Democrats who blocked expansion of the New Deal. Often referred to as "Mr. Republican", he co-sponsored the Taft–Hartley Act of 1947, which banned closed shops, created the concept of right-to-work states, and regulated other labor practices.

Wendell Lewis Willkie was an American lawyer, corporate executive and the 1940 Republican nominee for president. Willkie appealed to many convention delegates as the Republican field's only interventionist: although the U.S. remained neutral prior to Pearl Harbor, he favored greater U.S. involvement in World War II to support Britain and other Allies. His Democratic opponent, incumbent President Franklin D. Roosevelt, won the 1940 election with about 55% of the popular vote and took the electoral college vote by a wide margin.