With Max Baucus now confirmed as U.S. ambassador to China, Montana Gov. Steve Bullock (D) gets to appoint a temporary replacement for Baucus' seat.
And that pick is widely expected to be Lt. Gov. John Walsh (D), who is already running for Baucus' vacant Senate seat in November.
Selecting Walsh could give him a leg up in his Democratic primary, as well as boost his name identification for the general election.
Still, Montana remains a good 2014 pick-up opportunity for Republicans, given that President Obama got just 42% of the vote in the state in 2012. Then again, Sen. Jon Tester (D) was able to win re-election that year.
The front-runner for the GOP nomination in this Senate race is Rep. Steve Daines (R-Mo.).