Answer
Mick Enzi, the incumbent Republican senator, was challenged by Liz Cheney in the 2014 U.S. Senate Republican primary in Wyoming. Enzi had served in the Senate since 1997 and was seeking re-election to a fourth term. Cheney, the daughter of former Vice President Dick Cheney, was a political newcomer and served as the chair of the Wyoming Republican Party at the time of the election.