The Hill reports that Sen. Joe Manchin (D-WV) is considering leaving the Senate before the 116th Congress is over or after the 2020 election.

Manchin told The Hill he is frustrated by the “lack of bipartisan cooperation” and the “legislative stalemate” in Congress. He also “accused Senate Majority Leader Mitch McConnell  of turning the Senate into a “legislative graveyard.” The centrist Democrat from West Virginia became especially annoyed over the slow progress of a disaster relief bill last month and according to a Democratic senator, he spoke of “retiring before the end of the 116th Congress.” The anonymous Senator said that Manchin was fed up and told him, “‘I’m out of here. I’m going to be out of here.'”

The Hill spoke to two of his colleagues in the Senate. One said of Manchin, “All he says is, ‘I’ll be here until 2020.’”

The other, who traveled with him on a recent government trip to the Arctic region, noted that “he’s been fed up for a long time. He said, ‘I have so many people talking to me about whether I should or I shouldn’t [run for governor].’”

The colleague added, “One of the things you get as a lawmaker is you get lots of free advice from lots of people. He expressed frustration, and it’s the same that a lot of people share.”

Manchin told The Hill, “I haven’t been happy since I’ve been here. I’ve always thought there was more we can do. It’s the greatest body in the world, so much good could be done.” And he doesn’t find serving as a senator “nearly as fulfilling” as he did his time as governor.

Prior to running for the Senate, Manchin served as the governor of West Virginia, a job he thoroughly enjoyed. He said “supporters in the state are pressing him to run for governor next year” and “he’s considering it…We’re looking at all the different plays. I want to make sure whatever time I have left in public service is productive.”

If Manchin does decide to run for governor in 2020, it may be difficult for Democrats to retain Senate his seat. Trump carried the state of West Virginia in 2016 with 68.5% of the vote. And Manchin won reelection by only a “narrow margin in 2018, telling colleagues that the race “took a toll” on him.”

The Hill contacted West Virginia’s secretary of state’s to determine what state laws would apply in the event Manchin runs for governor in 2020 and wins. Erin Timony, assistant communications director, said, “The gray area is when the vacancy occurs.” According to Timony:

If he triumphs, Manchin could possibly appoint a fellow Democrat to replace him in the Senate, though it’s not a sure thing.

If Manchin resigns his Senate seat following the certification of the election but before he takes the gubernatorial oath of office, then the current Republican governor, Jim Justice, will appoint his successor.

Should Manchin resign his Senate seat just before taking the oath of office, then he could appoint his own successor as long as he does so before the notice of resignation reaches Justice’s office.

If Manchin ran for governor and lost, he could keep his Senate seat. Although he seems inclined to leave the Senate, if his staying meant the Democrats would hold a Senate Majority in 2020, he might be persuaded to stay on.

The Hill spoke to a former senior Senate aide who is now a Democratic strategist who believes that “Manchin is the only candidate who can keep the seat in Democratic hands.” The strategist also said the “chance of another Democrat winning a Senate race in the Mountain State is “less than zero.”

No one knows what Manchin will decide to do in the end, but the fact that he’s talking so openly about it makes it seem like a real possibility.

Although Manchin is a Democrat, he is a moderate. According to Fact Check, he has voted with President Trump 60% of the time. And he voted to confirm Brett Kavanaugh’s nomination to the Supreme Court last October.