After Roosevelt's hand-picked successor as president, former Secretary of War William Howard Taft, was inaugurated in March 1909, Congress battled over what became the Payne–Aldrich Tariff. At the time, tariffs were the main source of government revenue, and conflicts over them were passionate. The party platform had promised tariff reform, which progressive insurgents like Borah took to mean tariff reductions. Old Guard legislators like Senator Aldrich disagreed, and the final version actually raised rates by about one percent. The battles alienated Borah from Taft, who in a speech at Winona, Minnesota described the new law as the best tariff the country had ever had. Borah and other progressives had proposed an income tax to be attached to the tariff bill; when this was unacceptable to Taft, who feared the Supreme Court would strike it down again, Borah repackaged it as a constitutional amendment, which passed the Senate unanimously and then the House, and to the surprise of many, passed the requisite number of state legislatures by 1913 to become the Sixteenth Amendment.