The correct response regarding the election of 1912 is:
The Republican Party did not nominate Roosevelt because he was too progressive.
In the 1912 election, Theodore Roosevelt, who was a former president and a progressive reformer, ran as a candidate of the Progressive Party (also known as the "Bull Moose Party") after not securing the Republican nomination, which went to William Howard Taft. The election was notable for the split in the Republican Party, which allowed Woodrow Wilson, the Democratic candidate, to win the presidency.