Taggart remained active in national and state politics until his death in 1929. He served on the Democratic National Committee from 1900 to 1916 and as its chairman from 1904 to 1908. As the party's national chairman, Taggart ran Judge Alton B. Parker's campaign in the presidential election in 1904, but Parker lost to Theodore Roosevelt. Taggart played a key role in securing John W. Kern's Democratic nomination for U.S. vice president and Thomas R. Marshall's nomination for governor of Indiana in 1908, as well as Woodrow Wilson's nomination for U.S. president and Marshall's vice presidential nomination in 1912 at the Democratic National Convention in Baltimore, Maryland.