William Howard Taft faced the difficult task as President of living up to the legacy of Theodore Roosevelt. Taft so disappointed his predecessor, former mentor, and friend, that Roosevelt opposed his renomination in 1912 and bolted from the Republican Party to form his own "Bull-Moose" party, creating an opening for Democrat Woodrow Wilson in the 1912 presidential election. Taft's lifelong ambition was to serve as Chief Justice of the United States, to which he was appointed after leaving the presidency. He remains the only man in American history to have gained the highest executive and judicial positions.