In the Senate, Borah became one of the progressive insurgents who challenged President William Howard Taft's policies, though Borah refused to support former president Theodore Roosevelt's third-party bid against Taft in 1912. Borah reluctantly voted for war in 1917 and, once it concluded, he fought against the Versailles treaty, and the Senate did not ratify it. Remaining a maverick, Borah often fought with the Republican presidents in office between 1921 and 1933, though Calvin Coolidge offered to make Borah his running mate in 1924. Borah campaigned for Herbert Hoover in 1928, something he rarely did for presidential candidates and never did again.