Underwood sought the presidential nomination at the 1912 Democratic National Convention, but the convention selected Woodrow Wilson after forty-six ballots. He declined the vice presidential nomination, which instead went to Thomas R. Marshall. Underwood ran for president again in 1924, entering the 1924 Democratic National Convention as a prominent conservative opponent of the Ku Klux Klan. One of the few prominent anti-Klan politicians in the South at the time, Underwood and his supporters narrowly failed to win adoption of a Democratic resolution condemning the Klan. He experienced a boomlet of support on the 101st presidential ballot of the convention, but the Democrats nominated John W. Davis as a compromise candidate. Underwood declined to run for re-election in 1926 and retired to his Woodlawn plantation in Fairfax County, Virginia, where he died in 1929.