When Wilson invited the Foreign Relations Committee to the White House to informally discuss the treaty, Harding ably questioned Wilson about Article X; the president evaded his inquiries. The Senate debated Versailles in September 1919, and Harding made a major speech against it. By then, Wilson had suffered a stroke while on a speaking tour. With an incapacitated president in the White House and less support in the country, the treaty was defeated.[69]

Presidential election of 1920
Main article: 1920 United States presidential election
Primary campaign
Harding c. 1919
Most Progressives had rejoined the Republican Party, and their former leader, Theodore Roosevelt, was the overwhelming favorite for the 1920 Republican presidential nomination. When Roosevelt suddenly died on January 6, 1919, a number of candidates quickly emerged. These included General Leonard Wood, Illinois Governor Frank Lowden, California Senator Hiram Johnson, and a host of underdogs such as Herbert Hoover (renowned for his World War I relief work), Massachusetts Governor Calvin Coolidge, and General John J. Pershing.[70]
Harding, while he wanted to be president, was as much motivated in entering the race by his desire to keep control of Ohio Republican politics, enabling his re-election to the Senate in 1920. 