How was the election of 1912 different from previous presidential elections?

Before the election of 1912, there were actually two major parties that fought the elections. There were also a few small parties in thiose elections that were quiet insignificant. before the 1912 elections, the Republican party split into two parts and one of the section named it the Progressive party. They both carried certain amount of votes. This splitting actually helped the Democrats. Although at that time the Democrats did not have any chance of winning the presidential elections, but the splitting of the Republican Party helped them to win the election of 1912.

The answer is installation.