Rep. Adam Schiff publicly called on Wednesday for President Joe Biden to drop out of the presidential race, becoming the highest-profile figure in the Democratic Party to make such a move.

The California Democrat and Senate candidate cited “serious concerns” that Biden can successfully win against former President Donald Trump in November, according to a statement first obtained by the Los Angeles Times and later confirmed by HuffPost.

“Joe Biden has been one of the most consequential presidents in our nation’s history, and his lifetime of service as a Senator, a Vice President, and now as President has made our country better,” the congressman said in his statement.

“But our nation is at a crossroads. A second Trump presidency will undermine the very foundation of our democracy, and I have serious concerns about whether the President can defeat Donald Trump in November.”

During a campaign trip in Las Vegas, reporters asked Biden on Wednesday if he had any response to Schiff’s comments. The president did not stop to answer, according to the press pool.

As a loyal establishment Democrat, Schiff had been one of Biden’s strongest champions until recently. A spokesperson for the congressman declined to answer HuffPost’s question of whether Schiff believes his statement will sour his relationship with the president.

Schiff’s public support for Biden began dwindling after the president’s startlingly poor performance during his first debate against Trump. The event resulted in a wave of Democrats, mostly privately and sometimes publicly, expressing concern about whether the president should step aside and let a younger candidate serve as the party’s nominee.

Biden has since pushed back on those calls, doubling down on his decision to continue running for reelection. In an interview with BET News that aired Wednesday, the president said he would consider dropping out of the race if a doctor advised him to.

Schiff is a very close ally of former House Speaker Nancy Pelosi (D-Calif.), who has reportedly been fielding concerns from the Democratic caucus about Biden. It’s unclear if Pelosi was previously aware of Schiff publicly calling for Biden to drop out.

“While the choice to withdraw from the campaign is President Biden’s alone, I believe it is time for him to pass the torch. And in doing so, secure his legacy of leadership by allowing us to defeat Donald Trump in the upcoming election,” Schiff said in his statement.

“But make no mistake, whoever our party ends up nominating, or if the nomination remains with the president, I will do everything I can to help them succeed,” he continued. “There is only one singular goal: defeating Donald Trump. The stakes are just too high.”

Schiff hinted at his position on the matter earlier this month during an interview with NBC’s “Meet the Press,” where he told host Kristen Welker that he’s unsure of whether Biden has the “vigor” to defeat Trump.

“Given Joe Biden’s incredible record, given Donald Trump’s terrible record, he should be mopping the floor with Donald Trump. Joe Biden’s running against a criminal. It should not be even close,” he said in the July 7 interview. “And there’s only one reason it is close, and that’s the president’s age.”

On Saturday, Schiff warned donors during a private fundraiser that the Democratic Party will likely face overwhelming losses in this year’s election if Biden were to remain the nominee, The New York Times reported on Tuesday.

“I think if he is our nominee, I think we lose,” he reportedly said. “And we may very, very well lose the Senate and lose our chance to take back the House.”