• Rep. Mikie Sherrill of New Jersey became the latest Democratic lawmaker to publicly urge President Joe Biden to end his reelection bid.
• House Democrats convened for a pivotal meeting as members weigh whether to continue backing Biden's besieged campaign.
• It was the first full caucus meeting since Biden's disastrous debate against Trump sparked a campaign crisis.
• At least nine sitting House Democrats have called for Biden to drop out of the race, according to NBC News.

Rep. Mikie Sherrill of New Jersey on Tuesday became the latest Democratic lawmaker to publicly urge President Joe Biden to end his reelection bid and allow a new nominee to compete against former President Donald Trump.

"When I think of my four children and all of the rights that another Trump presidency endangers, and in light of the recent Supreme Court decision that gave inordinate power to the President of the United States, the stakes are too high – and the threat is too real – to stay silent," Sherrill said in a 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," she said.

Sherrill is the seventh House Democrat who is openly calling for Biden's withdrawal and the ninth overall, according to NBC News' tally.

Her statement came hours after House Democrats convened at their national party headquarters in Washington for a pivotal caucus meeting, as members weigh whether to continue backing Biden's besieged campaign or seek to replace him.

Lawmakers had no access to their phones during the closed-door meeting, which marked the first time the full caucus has assembled since Biden's disastrous debate against Trump in June sparked a full-blown campaign crisis.

Many members refused to answer reporters' questions as they trickled out of the building after the meeting Tuesday morning.

"I promised I wouldn't talk at all about what was said," Rep. Mike Quigley, D-Ill., told NBC News as he departed.

When a reporter asked Rep. Steve Cohen, D-Tenn., if Democrats were on the same page, Cohen replied, "No ... we're not even in the same book."

Cohen also told an Axios reporter that some members in the caucus meeting said that Biden should withdraw. A spokesman for Cohen did not respond to CNBC's request to confirm that comment.

Senate Democrats held their own meeting on Capitol Hill on Tuesday afternoon.

Biden's feeble, raspy showing in the debate set off panic among Democrats, prompting some top donors, pundits and allies to openly urge Biden, 81, to abandon his bid for another four years in office.

Rep. Jerry Nadler, D-N.Y., who also called on Biden to drop out, said Tuesday that he now backs the incumbent.

"I'm fully supportive of him. I plan to campaign for him. And it's essential that he wins," Nadler said.

But Rep. Lori Trahan, D-Mass., expressed deep reservations about Biden's continued candidacy.

"Since the debate, I have met with fellow Biden voters in Massachusetts who have real concerns about the President's ability to beat Donald Trump. I share those concerns," Trahan, the co-chair of the Democratic Policy and Communications Committee, told NBC in a statement Tuesday.

"While President Biden has made clear he feels he is the best candidate to win this election, nothing that has happened over the past twelve days suggests that voters see things the same way," Trahan said.

"A second Trump presidency will do irreparable damage to women and to our country, and President Biden must act with urgency to restore Americans' confidence so we win in November."

Overall, however, only a few Democratic lawmakers have gone on record calling for a change at the top of the ticket — an immensely risky move less than four months out from Election Day.

Biden has rejected calls to step aside, saying he believes he is still the best person to compete against Trump in the presidential election. He has worked since the debate to shore up support from key blocs, including the Congressional Black Caucus and the Congressional Hispanic Caucus.

"I'm standing with President Joe Biden and Vice President Kamala Harris and we're going to continue to do the work that needs to get done," Congressional Hispanic Caucus chair Nanette Barragan, D-Calif., said on MSNBC after the caucus meeting Tuesday morning.

Barragan described that meeting as a "family conversation to hear out our colleagues," but added, "those are private conversations."

Democratic leaders have issued terse statements of support for the Biden-Harris ticket.

"I made clear publicly the day after the debate that I support President Joe Biden and the Democratic ticket. My position has not changed," House Democratic Leader Hakeem Jeffries of New York told reporters Monday evening.

Senate Majority Leader Chuck Schumer, D-N.Y., has said he backs Biden.

Outside the Democratic National Committee building, a handful of protesters, clad in sunglasses and suits, held up all-caps signs asking, "Is Joe Biden fit for office?!"

The protesters said they were from the National Republican Campaign Committee, Politico reported.

Correction: A previous version of this story misidentified the state represented by Rep. Jerry Nadler. He represents New York.