NON-PLAYER OF THE WEEK: Brian Schweitzer

Former Montana Gov. Brian Schweitzer (D) was widely expected to launch a bid for retiring Sen. Max BaucusMax Sieben BaucusBooker tries to find the right lane  Top Lobbyists 2017: Hired Guns GOP tries to keep spotlight on taxes amid Mueller charges MORE’s (D-Mont.) seat, but over the weekend, he opted against it.

“There are all kinds of people that think I should be in the U.S. Senate,” Schweitzer said. “But I never wanted to be in the U.S. Senate. I kicked the tires. I walked to the edge and looked over.”

It was a head-scratching decision by the 57-year-old politician, who ran unsuccessfully for the upper chamber in 2000. He is popular in Montana and was seen as the party’s best shot to retain the seat in the red state. 

Schweitzer had touted polls showing that he could beat Baucus in a primary. Earlier this year, Baucus, who is not fond of Schweitzer, stunned Washington by announcing he would not run for reelection.

Schweitzer’s decision has left Democrats scrambling for a substitute and has increased the chances that the GOP will take control of the Senate in 2015. Republicans have to pick up six seats to claim the majority — no easy task.

The problem for Democrats is that nearly everyone thought Schweitzer was going to run. Sen. Jon TesterJonathan (Jon) TesterAnother perfect storm: Why we must act before flood insurance runs dry Democrats scramble to contain Franken fallout  GOP campaign committees call on Democrats to return Franken donations MORE (D-Mont.) last month said he “would bet the farm” on it.

There is plenty of speculation about why Schweitzer reversed course. The National Republican Senatorial Committee noted that it had done extensive opposition research on the former governor.

The announcement also came a day before the Great Falls Tribune ran a hard-hitting report on Schweitzer’s ties to a pair of mysterious dark money political groups.

The end result is that Republicans are now favored to win the Montana seat. In 2012, Mitt Romney defeated President Obama in the state by nearly 14 percentage points. Rep. Steve Daines (R-Mont.) is expected to launch his Senate campaign in the coming weeks.