Max Baucus
Max Sieben Baucus (né Enke; born December 11, 1941) is a retired American politician and diplomat who served as a United States Senator from Montana from 1978 to 2014. A member of the Democratic Party, he was a U.S. Senator for nearly 36 years, making him the longest-serving Senator in Montana history. President Barack Obama appointed Baucus to replace Gary Locke as the 11th United States Ambassador to China, a position that he held from 2014 until 2017.
John Walsh (U.S. senator)
On October 3, 2013, Walsh announced his intention to run for the seat of retiring Senator Max Baucus. On February 9, 2014, Walsh was appointed to replace Baucus in the Senate after Baucus stepped down early to become U.S. Ambassador to China, making Walsh the incumbent in the race. Rancher Dirk Adams and former Montana Lieutenant Governor John Bohlinger also ran for the Democratic nomination.