He was chosen as the Democratic nominee for president on the forty-fourth ballot of the 1920 Democratic National Convention. Running on a ticket with future President Franklin D. Roosevelt as his vice presidential running mate, Cox suffered the worst popular vote defeat (a 26.17% margin) since the unopposed re-election of James Monroe in 1820 as the country accepted Republican nominee Warren G. Harding's call for a "return to normalcy" after the Wilson years.