Dem
51
GOP
49
Democrats are worried silly about holding the Senate in 2024. Democratic incumbents Jon Tester (MT), Joe Manchin (WV), and Sherrod Brown (OH) are all in red states. If any one of them were to retire, their seat would be lost, no ifs ands, or buts.
Democrats got some good news yesterday when Tester announced that he wants a fourth term in order to defend "Montana values."
Of the three, Tester's seat is the most solid. His personal approval rating is north of 60%. Also, although Montana almost always goes for Republicans in the Electoral College, since World War II, only three Republicans have been elected to the Senate from the state. Otherwise, Democrats have dominated it. Also, Democrats have been elected governor of Montana many times, so the state isn't as red as it might seem from the presidential results. This is not to say Tester will be a shoo-in, but he has personally won three Senate races in Montana and has a high approval rating. This doesn't scream "hopeless."
Montana has two Republican representatives, Ryan Zinke and Matt Rosendale. Either or both of them could jump in. So could other statewide officials and members of the state legislature. There is likely to be a bruising primary whereas Tester won't face a serious primary opponent.
Over in Ohio, Sen. Sherrod Brown (D-OH) is also running for a fourth term. His situation is more precarious than Tester's because Ohio hasn't been electing Democrats statewide left and right recently. Nevertheless, he is a popular incumbent and his blend of progressivism on some issues and centrism on others is a good fit. He has a good chance.
The final one in the trio is Manchin. He hasn't announced anything yet. In addition to a possible Senate run, he could also decide to run for the governorship in 2024, which will be open because Gov. Jim Justice (R-WV) is term-limited and toying with a Senate run. If he ran, Manchin would be in for one hell of a fight and might decide it is not worth it, especially since Democrats keep dumping on him. (V)