There are Senate elections in 2020 in a third of the states. Among those are Colorado, Georgia, Montana, and Texas. All of these are states Democrats need to win to take back the U.S. Senate. Of them, Colorado is probably going to be their best bet and it will be offset by a Democrat loss in Alabama.
It is somewhat surprising that Democrats are fielding presidential candidates from all of those states save Georgia and might see Stacey Abrams enter from Georgia. John Hickenlooper, Colorado’s Governor, prefers to run for President. Montana Governor Steve Bullock wants to run for President. Both Beto O’Rourke and Julian Castro from Texas are running for President.
The odds are that none of these people will be the Democratic nominee for President. Perhaps they can be Vice President. But their states do not currently have credible Democrat challengers for the Senate.
Republicans will be on defense in 2020, fighting to keep both the White House and their Senate majority. It would be a perfect time to fight for control of the Senate. But few Democrats seem really interested.
This all suggests Democrats know the Senate is not as much in play as some would claim.