Question: What  attorney and an American politician of the Democratic Party in Montana was was challenged in the Democratic primary by Leif Erickson in an  election in Montana ?
Sentence (from "United States Senate election in Montana, 1946"): Incumbent United States Senator Burton K. Wheeler, who was first elected to the Senate in 1922, and was re-elected in 1928, 1934, and 1940, ran for re-election.
Relevant evidence: No