Sen. Joe Manchin III (I-W.Va.) is considering re-registering as a Democrat to compete for the party’s presidential nomination in the wake of President Biden’s announcement Sunday that he will exit the campaign, according to a Manchin adviser.

The adviser, Jonathan Kott, declined to share more details about Manchin’s plans at this stage. Manchin was the first elected official to signal an openness to challengingVice President Harris in the wake of Biden’s announcement after the president endorsed Harris, as did some members of the Democratic establishment.

Manchin, who will turn 77 next month, left the Democratic Party in May to register as an independent. The then-Democrat from a red state, who irked some of his fellow Democrats by cutting deals with Republicans, announced in the fall that he would not seek reelection to his Senate seat at the end of his term, hampering Democratic hopes of holding on to their Senate majority in 2024.

Previously, Manchin had flirted with mounting a third-party presidential campaign this cycle as some Democrats, even before Biden’s halting June 27 debate performance, worried about the lack of enthusiasm for the president among a broad swath of Democratic voters. But in February, Manchin said he would “not be involved in a presidential run” as he did not want to be a “spoiler” in a race then presumed to be between Biden and former president Donald Trump.

“I just don’t think it’s the right time,” Manchin said then. “Democracy is at stake right now.”

Another long-shot candidate also announced her intention Sunday night to vie for delegates at next month’s Democratic National Convention, where the Democratic nomination will be settled.

Marianne Williamson, a self-help author and motivational speaker who unsuccessfully ran for the 2020 and 2024 Democratic presidential nominations, also announced she would compete for the spot (after previously exiting the race and reentering).

“I look forward to taking my message to the American people, and convincing Democratic delegates, that I am the best candidate to take us to victory in November,” she wrote on X.

Manchin has long been a thorn in Democrats’ side, even as he also helped deliver Biden some of his signature policy achievements, including the Inflation Reduction Act, which included many sweeping climate change measures. (Manchin renamed that bill before finally supporting it.)The moderate has also clashed with Biden over energy policy and other matters, but has said he could not vote for Trump.

Manchin’s reported consideration of a presidential bid was in sharp contrast to dozens of Democratic lawmakers who rushed Sunday to endorse Harris for the top of the Democratic ticket. Several Democratic governors who had been floated as possible candidates, in the event of a vacancy on the ticket, also endorsed Harris.

In an interview Sunday morning with CBS News’s “Face the Nation,” before Biden’s exit from the race, Manchin said he would not run for a spot on the Democratic ticket.

“No, this is a new generation, Margaret,” he told moderator Margaret Brennan. “We’ve got a lot of deep people on the bench to conserve, and they have proven their mettle by being in an executive position. Give them a chance to rise.”

In another interview on Sunday morning, this time with CNN’s “State of the Union,” Manchin said he favored an “open process” to determine a replacement for Biden, who at that point had not yet made his announcement.

Manchin said an open process, rather than handpicking a successor, would be the best way to showcase to voters the deep bench of talent in the Democratic Party. He mentioned two Democratic governors, Kentucky’s Andy Beshear and Pennsylvania’s Josh Shapiro, as strong potential candidates, but did not mention Harris.

Both governors, Manchin said, “are operating with legislatures either evenly split or completely opposite their party affiliation. They haven’t divided their state. They haven’tmade you pick a side and demonize the other side. They’ve brought people together.”

Manchin said Trump’s running mate, Sen. J.D. Vance (R-Ohio), may appeal to voters in Manchin’s home state who feel left behind by the Democratic Party.

“I think he has enough of a flavor there and everything,” Manchin said. “I grew up in another era of Appalachia, but I can see it. I’ve watched my state change like no other state for 80 years.”

Douglas MacMillan contributed to this report.