Sen. Peter Welch (Vt.) has become the first Democratic senator to call for President Biden to step aside following his June debate.

“We cannot unsee President Biden’s disastrous debate performance,” the freshman senator wrote in a Washington Post op-ed published Wednesday evening. “We cannot ignore or dismiss the valid questions raised since that night.

“For the good of the country, I’m calling on President Biden to withdraw from the race,” Welch said.

The senator cited polling “shifts” in Minnesota, New Hampshire, Nevada, Arizona and Georgia to make the case that the political peril was too great for Biden to stay in the race because of the risk that Donald Trump might win.

Democratic lawmakers continue to question Biden’s viability as a candidate and panic over their party’s prospects in the fall. Twelve members of the House have called on Biden to step aside. Several senators privately expressed concerns in a closed-door meeting Tuesday that Biden has no path to victory in 2024 and that his unpopularity risks Democrats losing both the House and Senate. Sen. Michael Bennet (D-Colo.) said in a CNN interview Tuesday night that he feared Trump would win in a “landslide” but stopped short of asking Biden to step aside.

Former House speaker Nancy Pelosi (D-Calif.), in a TV interview on Wednesday, also urged Biden to quickly decide whether he is running, despite Biden insisting he is staying in the race.

“We’re all encouraging him to make that decision, because time is running short,” Pelosi said.

On Thursday, top Biden officials Mike Donilon, Jen O’Malley Dillon, and Steve Ricchetti will brief Senate Democrats at lunch at the Democratic Senatorial Campaign Committee. Senate Majority Leader Charles E. Schumer (D-N.Y.) invited them to address his caucus’s concerns.

“As I have made clear repeatedly publicly and privately, I support President Biden and remain committed to ensuring Donald Trump is defeated in November,” Schumer said in a statement Wednesday evening.

The position puts Welch at odds with his fellow Vermonter, Sen. Bernie Sanders, who told reporters Wednesday that he believed Biden could win and has urged people to focus on Biden’s policies.

Earlier on Wednesday, Welch said he hoped Biden would decide to exit the race after he saw the polling data. “President Biden has made it clear that he’s all in, but the evidence continues to come in about how an uphill battle is turning into an up-mountain battle,” the senator said.

Biden has told Hill Democrats that he is running and wants the debate about his candidacy to end.

“I am firmly committed to staying in this race, to running this race to the end, and to beating Donald Trump,” he wrote them in a letter sent Monday.

On Wednesday, Cook Political Report analyst David Wasserman described Trump’s lead in the polls post-debate as “the most drastic shift in the race all year.”

In his op-ed, Welch praised Biden for his years of service, saying that he has “united” the party and helped created a bench of elected officials who can defeat Trump. He called Vice President Harris a “capable” leader and also praised other unnamed Democratic governors and senators.

“I understand why President Biden wants to run,” he wrote. “He saved us from Donald Trump once and wants to do it again. But he needs to reassess whether he is the best candidate to do so. In my view, he is not.”