Answer:
The primary received its first major test in the 1912 election pitting incumbent president William Howard Taft against challengers Theodore Roosevelt and Robert La Follette.
Explanation:
More details about Primary elections: In primaries, party members vote in a state election for the candidate they want to represent them in the general election. After the primaries and caucuses, each major party, Democrat and Republican, holds a national convention to select a Presidential nominee.
