If Democrats want to regain control of the US Senate in 2020, They must win 7 GOP held seats.

[boomer_wv]

3. Manchin

There is a 0% chance that Manchin would switch parties. He just won reelection last year, if he were going to switch he would have done so back then when he was in the toughest reelection of his life. Instead he took on a Trump backed Republican candidate who has held statewide office and beat him. The risk isn't that Manchin could become a Republican, it's that he could decide to run for Governor and win. Of course, if he did that he would be able to appoint his replacement. That seat would be back up for a special in 2022, however.

I also find it somewhat unlikely that Peters would lose in Michigan. Trump won the state by less than .25 points. That's just about 10,000 votes out of 4.5 million. That's an eyelash. Peters won in 2014 by 13 points, although his opponent essentially torpedoed her own campaign. The 2014 political environment was much worse for Democrats than the 2020 one looks to be though. Plus, the top Republican candidate currently just lost a Senate bid last year.