As a member of the Republican Party , Roosevelt had served as President from 1901 to 1909 , becoming increasingly progressive in the later years of his presidency . In the 1908 presidential election , Roosevelt helped ensure that he would be succeeded by Secretary of War Taft . Although Taft entered office determined to advance Roosevelt 's Square Deal domestic agenda , he stumbled badly during the Payne – Aldrich Tariff Act debate and the Pinchot – Ballinger controversy . The political fallout of these events divided the Republican Party and alienated Roosevelt from his former friend . Progressive Republican leader Robert La Follette had already announced a challenge to Taft for the 1912 Republican nomination , but many of his supporters shifted to Roosevelt after the former President decided to seek a third presidential term , which was permissible under the Constitution prior to the ratification of the Twenty-second Amendment . At the 1912 Republican National Convention , Taft narrowly defeated Roosevelt for the party 's presidential nomination . After the convention , Roosevelt , Frank Munsey , George Walbridge Perkins and other progressive Republicans established the Progressive Party and nominated a ticket of Roosevelt and Hiram Johnson of California at the 1912 Progressive National Convention . The new party attracted several Republican officeholders , although nearly all of them remained loyal to the Republican Party — in California , Johnson and the Progressives took control of the Republican Party
1912 Progressive National Convention
1912 Progressive National Convention
Progressive Party (United States, 1912)