The correct answer to this open question is the following.
The Republican Party try to limit the influence of Theodore Roosevelt by naming William Howard Taft as the Republican candidate for the 1912 election.
Roosevelt and Taft had been friends, but political differences split them. At that time both expressed harsh comments about the other. Taft called Roosevelt "a great menace." Roosevelt called Taft "a dishonest politician." So the Republican National Committee gave 235 delegates to Taft and only 19 to Theodore Roosevelt. This angered Roosevelt and formed its own party.
