As President Biden prepared to address NATO allies gathered in Washington on Tuesday evening, his advocates on Capitol Hill seemed to be growing a bit louder. But so was the unease over Democratic prospects of beating Donald Trump and making gains in Congress come November.

In a searing indictment of the stakes for Democrats, Sen. Michael Bennet (Colo.) went on CNN Tuesday night and said that as things stand, Trump would win in a “landslide” in November.

“Donald Trump is on track I think to win this election and maybe win it by a landslide and take with him the Senate and the House,” Bennet said, echoing concerns he raised in a Tuesday lunch with his colleagues. “For me, this isn’t a question about polling, it’s not a question about politics. It’s a moral question about the future of our country.”

Bennet has yet to call for Biden to explicitly step aside in the wake of his faltering debate performance less than two weeks ago.

“We’re all here this week to have this discussion, to have this debate,” Bennet said. “The White House, in the time since that disastrous debate, I think has done nothing to demonstrate that they have a plan to win this election … they need to do that.”

Bennet said it’s not just party elites, as Biden has argued, but voters who have “deep concerns” about Biden’s age and ability to serve another four years in the White House. “These are my voters who have said to me, ‘I’ve been through this with my mom, I’ve been through this with my dad. I’m terrified about what it will mean if Donald Trump is elected president again in this country.’”

Nonetheless, Bennet stated that no other Senate Democrat explicitly called for the president to step aside in a gathering of Democratic senators on Tuesday midday. But others like Sen. Jon Tester (D-Mont.), who is in a tough reelection race, did say they seriously doubted Biden could win the presidential contest, according to two people briefed on that meeting.

The fissures among Democrats were indicative of the wide split created by Biden’s defiant decision to stay in the presidential contest following a debate performance in which he sometimes didn’t finish his thoughts and at times seemed confused. No Senate Democrats have publicly called for Biden to step aside — yet — and only 10 House Democrats have done so.

Instead, there was a rising tide of resignation from some Capitol Hill Democrats, enthusiasm from others — and despair and anger from still more — that the president would remain atop the ticket and be their nominee in November. Hill Democrats were also holding their breath ahead of a rare Thursday news conference, the first time since the debate that the president planned to entertain freewheeling questions from the press.

Before a meeting of Senate Democrats, Sen. Chris Coons (D-Del.), co-chair of Biden’s campaign, said the president had heard the message from lawmakers that he needed to get out and do more events and interviews.

“We need to remember that President Biden for 30 years has been someone who has a stutter, who occasionally misspeaks … and not judge him by too high a standard,” Coons said.

In many ways, things stayed somewhat steady in terms of Biden’s fate on Capitol Hill, where Rep. Mikie Sherrill — who represents a competitive New Jersey district — became the 10th House member to publicly or privately call on Biden to abandon his reelection campaign.

“I know that President Biden and his team have been true public servants and have put the country and the best interests of democracy first and foremost in their considerations,” Sherrill said in a lengthy statement. “And because I know President Biden cares deeply about the future of our country, I am asking that he declare that he won’t run for reelection and will help lead us through a process toward a new nominee.”

Sherill said in a brief interview that she believes Vice President Harris would be a “fantastic nominee.”

Harris, meanwhile, kicked off a campaign sprint aimed at energizing key Democratic constituencies, just as she has became the subject of intense speculation about whether she would be the nominee if Biden chose to exit the contest. Harris has fiercely defended Biden since the debate and insists he will be the nominee.

And the Democratic drama is playing out just days before Republicans intend to formally nominate Trump at their convention in Milwaukee and he is expected to announce his vice-presidential nominee.

In the Senate on Tuesday, few Democrats left a caucus-wide luncheon offering full-throated endorsements of Biden’s campaign.

Following a meeting of his colleagues, Sen. Richard Blumenthal (D-Conn.) acknowledged that some Democrats do not currently want Biden to remain atop the ticket in November. But he suggested that the president could win back their support.

“The Democratic candidate is Joe Biden, and he has my support,” Blumenthal said. “I think he needs to continue effectively and aggressively making his case to the American people, and earning their support as well as a number of my colleagues.”

While no sitting senator has publicly called on the president to exit the race, some want Biden to do more to prove that he can beat Trump in November.

One GOP senator who is no Trump fan, Lisa Murkowski (Alaska), said she’d appealed to Sen. Joe Manchin III, an independent from West Virginia who is retiring, nudging him to reconsider entering the presidential contest (he declined, she said).

Sen. Dick Durbin (D-Ill.), the No. 2 leader of the caucus, exited the meeting still unsure of Biden’s standing, wanting the entire presidential campaign team to show it can defeat Trump.

“It still remains to be seen. He’s putting together a campaign that’s going to demonstrate whether he’s ready to beat Donald Trump,” Durbin told reporters.

House Democratic leader Hakeem Jeffries (N.Y.) and Senate Majority Leader Charles E. Schumer (D-N.Y.) have offered support for Biden so far, as the president has ramped up pressure on lawmakers to stick with him, vowing defiantly to stay in the race. Despite the public show of unity, however, dissension and concern still surround Biden’s decision to continue running and what it might mean for Democrats’ chances of making gains in Congress in November’s elections.

After the Tuesday morning meeting, House Democratic Caucus Chair Pete Aguilar (Calif.) echoed an adage from former speaker Nancy Pelosi (D-Calif.) when he said, “Unanimity is not the same as unity.”

“Let’s see the press conference. Let’s see the campaign stops. Let’s see all of this because all of it is going to be necessary,” Aguilar said about the public and private rift among the rank and file.

According to numerous House Democratic lawmakers and aides who spoke to The Washington Post, there was a feeling entering this week that concerns over Biden’s ability to beat Trump could amount to dozens of lawmakers soon calling on him to step aside.

But that movement appears to have been blunted after the Congressional Black Caucus — often described as the “conscience of Congress” — embraced Biden, and House members are now cautious about whether to call on Biden to leave the race, according to three people familiar with the dynamics.

As they trickled out of the Democratic National Committee’s headquarters Tuesday morning, some House Democrats expressed brief support for Biden and at times gave stilted comments to reporters. The meeting was described as a “family discussion” where members spoke openly and passionately about the somber moment in which they find themselves. There was no agreement on a course of action — though many accepted that it would be Biden’s choice alone to step aside. Some also worried that if Democrats don’t stop griping and quickly close ranks behind their nominee, they will be penalized by voters in November.

Multiple House Democratic lawmakers and aides, who spoke on the condition of anonymity to freely discuss the meeting, said there remains a pervasive feeling among House Democrats and campaign strategists that the president’s “age issue will continue to be a huge distraction.”

“They’re also worried about his decline,” a member said, referring to questions about Biden’s cognitive health after the debate. “There were people on both sides of the issue who spoke.”

Rep. Jerry Nadler (D-N.Y.) — who just two days ago privately called for Biden to leave the ticket — said that, while he still has concerns about the president’s candidacy, those are now “beside the point.”

“He’s going to be our nominee, and we all have to support him,” Nadler said.

A majority of House Democrats, however, dodged the media or said they would not discuss the meeting. They had been warned about leaking after lawmakers were struck by public reporting based on a private virtual meeting Sunday in which some members said they wanted Biden to step aside.

A person familiar with the House Democratic conversation, who spoke on the condition of anonymity to freely discuss internal dynamics, said the mood also shifted Monday when more-liberal members of the party, including Rep. Alexandria Ocasio-Cortez (N.Y.), began saying that Biden is the clear Democratic nominee and they will work to reelect him.

“You can’t be less supportive than ‘the Squad’ is going to be,” the person said, referring to the group of progressive House Democrats who have at times clashed with the president on politics and policy.

Rep. Ro Khanna (D-Calif.), a Biden campaign surrogate, said in an interview with Washington Post Live on Tuesday that most people agree that Biden is “an underdog at this point” — but an underdog who still has a path to win the presidency.

And Rep. Diana DeGette (D-Colo.), head of the House Pro-Choice Caucus, released a statement saying that Biden is “still up to doing the job for a second term.”

“Looking ahead, it is a waste of time and potentially dangerous for Democrats to spend the next few months wringing our hands trying to find an alternative path forward. President Biden has been a very successful president: defending our reproductive rights, protecting our environment, and upholding the values of our democracy. Meanwhile, Trump is a crazy felonious authoritarian,” she said.

One House Democrat from a swing district, speaking on the condition of anonymity to discuss a private conversation, said that “everyone’s dealing with the issue of having to outperform the top of the ticket.”

“So the question is, do we take back the House?” the member said. When asked if there is consensus on Biden, the lawmaker said, “Everyone understands he’s got to make that decision.”

Later in the evening, President Biden welcomed NATO leaders to Washington for its 75th annual gathering and touted the renewed strength of the alliance — pointing to the addition of two countries, Finland and Sweden — and the dramatic increase in countries spending at least 2 percent of their GDP on defense.

“This remarkable progress is proof that our commitment is broad and deep, that we’re ready, that we’re willing, we’re able to deter aggression and defend every inch of NATO territory across every domain,” Biden said. “It’s good that we’re stronger than ever because this moment in history calls for our collective strength.”

The president spoke passionately about the importance of the alliance. He did not mention Trump by name — who has threatened to shred the alliance and said he would allow Russia to do “whatever the hell they want” to any NATO country that doesn’t spend enough — but stressed that a bipartisan majority of Americans support the alliance and spoke of the danger of a world without it.

“The American people understand what would happen if there was no NATO, another war in Europe, American troops fighting and dying, dictators spreading chaos,” Biden said. “They know we’re strong with our friends, and we understand this is a sacred obligation.”

Theodoric Meyer, Liz Goodwin, Leigh Ann Caldwell, Paul Kane, Yasmeen Abutaleb and Abbie Cheeseman contributed to this report.