He died of heart attack and was succeeded by Vice President Calvin Coolidge. Harding took office after defeating Democrat James M. Cox in the 1920 presidential election. Running against the policies of incumbent Democratic President Woodrow Wilson, Harding won the popular vote by a margin of 26.2 percentage points, which remains the largest popular-vote percentage margin in presidential elections since the end of the Era of Good Feelings in the 1820s. His administration's economic policy was formulated by Secretary of the Treasury Mellon, who proposed cuts to the excess profits tax and the corporate tax. The central tenet of Mellon's tax plan was a reduction of the surtax, a progressive income tax that only affected high-income earners. To aid these veterans, the Senate considered passing a law that gave veterans a $1 bonus for each day they had served in the war. Harding opposed payment of a bonus to veterans, arguing that much was already being done for them and that the bill would 'break down our Treasury, from which so much is later on to be expected.'