In a message to congressional Democrats, U.S. President Joe Biden stood firm against calls for him to abandon his candidacy and urged to "end" the drama within the party that has torn Democrats apart since his poor performance in the general debate.

Biden's efforts to support the increasingly anxious Democratic Party came on Monday as lawmakers returned to Washington facing a choice: to decide whether to work on reviving his campaign or to oust the party leader, a critical time for his reelection and their political futures.

Biden wrote in the two-page letter that "the question of how to move forward has been well posed for over a week now. It is time to end it." He emphasized that the party has "one job," which is to defeat presumptive Republican presidential nominee Donald Trump in November.

Biden added in the letter distributed by his reelection campaign: "We have 42 days until the Democratic convention and 119 days until the general election." "Any weakness of resolve or lack of clarity about the upcoming mission not only helps Trump but also harms us. It is time to come together and move forward as a united party and defeat Donald Trump."

Concerns are growing as senior Democratic lawmakers join calls for Biden to step down despite his defiance. At the same time, some of the president’s staunchest supporters are doubling down on their fight for Biden’s presidency, insisting that no one is better positioned to defeat Trump in what many see as one of the most consequential elections of a lifetime.

As lawmakers weigh whether Biden should stay or go, it seems there are no easy answers.

It is a very fragile and volatile turn for the president's party. Democrats who have worked alongside Biden for years – if not decades – and cherished his lifelong work in policy priorities are now facing uncomfortable questions about his political future. These questions unfold as Biden hosts world leaders at the NATO summit this week in Washington.

Time is not in their favor, with nearly a month to go before the Democratic National Convention and just one week before Republicans gather in Milwaukee to renominate Trump as presidential choice. Many Democrats argue that the focus should instead be on condemning the former president over a felony charge in the hush-money case and pending federal charges in his attempt to overturn the 2020 election.

This may be what Biden himself would call a turning point. While he defiantly states that he will only step down if the Almighty comes and tells him to, Democrats in the House and Senate are deciding how much they want to challenge the president to change course, or whether they want to change course at all.

In a bid for "consensus," House Democratic Leader Hakeem Jeffries is calling legislators to private meetings before he shows his own preference, according to a person familiar with the situation who granted anonymity to discuss it. He plans to gather Democrats on Monday who are seen as most at risk in their reelection efforts.

But a private call on Sunday among about 15 members of the House committee revealed the deepening divide as at least four Democrats – Reps. Jerrold Nadler of New York, Jim Himes of Connecticut, Adam Smith of Washington, and Mark Takano of California – privately stated that Biden should step down.

Nadler, as the most senior member on the call, was the first to speak up and say that Biden should step down, according to a person familiar with the call who requested anonymity to discuss it. He did so aware of his seniority and that it would allow others to join him.

Several others on the call raised concerns about Biden's capabilities and chances of winning reelection, even though they stopped short of saying that Biden should withdraw from the race.

Other members, including Rep. Maxine Waters of California and Rep. Bobby Scott of Virginia, both leaders in the congressional Black Caucus, spoke forcefully in support of Biden, as did Rep. Richard Neal of Massachusetts, the top Democrat on the powerful Ways and Means Committee.

Many lawmakers appeared frustrated that leadership has not provided direction or a path forward, according to people familiar with the call. One Democratic lawmaker said, regardless of the decision, the "situation needs to end now," said one person.

Neal later stated that the bottom line is that Biden defeated Trump in 2020 and "will do it again in November."

The turmoil is also testing a new generation of leaders, headed by Jeffries and Senate Majority Leader Chuck Schumer. Both New Yorkers have refrained from publicly guiding lawmakers on a path forward as they balance diverse opinions within their ranks.

Behind the scenes, former House Speaker Nancy Pelosi, who continues to receive calls from lawmakers seeking advice on the situation, is viewed widely as the individual to watch for any final decision on Biden's future due to her closeness to the president and her skills in navigating party politics.

Pelosi spoke last week, saying that Biden's debate performance raised "legitimate" questions that needed to be answered, but she has remained supportive of the president. Biden called her last week when he reached out to other party leaders.

When Biden’s primetime interview on ABC Friday seemed to do little to soothe anxious Democrats – with some saying it made things worse – Pelosi stepped forward to publicly praise Biden on social media as a "great president who continues to deliver what America's kitchen needs." She added, "And we are not done yet!"

Schumer maintained a lower profile during the turmoil but will hold a meeting with Democratic senators on Tuesday for a weekly lunch where senators are sure to express a variety of viewpoints.

One Democrat, Senator Mark Warner of Virginia, planned to gather senators on Monday to discuss Biden privately, but a person familiar with the matter said that those talks will take place at the usual Tuesday party caucus lunch with all Democratic senators.

Another Democrat, Senator Alex Padilla of California, stated that "it’s time to stop complaining and get back to door-knocking."

Padilla spoke with Biden over the weekend, urging his campaign to "let Joe be Joe."

Padilla said Sunday, "Given the discussion, I think the campaign has no choice," explaining that Biden needs to hold public meetings and unplanned events to showcase "the Joe Biden I know, and that most people in America have come to love."

While some deep-pocketed donors may express discomfort, strategists working on House and Senate races say they have experienced record fundraising as donors view congressional Democrats as a "firewall" and last line of defense against Trump.

Democrats in the House have seen some of their best fundraising days yet, including $3 million on Friday night following the debate at an event with former President Barack Obama and Jeffries in New York City. This is in addition to $1.3 million transferred to the Democratic Congressional Campaign Committee during and immediately after the debate.

Senate Democrats are also seeing an "uptick" in support, according to a national Democrat familiar with Senate races.

As Democratic candidates campaign alongside Biden, the advice has been to focus on building their own brands and amplifying how the work done in Congress affects their local areas.