WASHINGTON — As members of Congress flee the capital for Thanksgiving break, a growing schism inside the Democratic Party is complicating Rep. Nancy Pelosi's bid to be the next speaker of the House.

Since Democrats recaptured the House majority last week, the California congresswoman — who is already the first woman to serve as speaker — has been working overtime to win the support of her members for an encore while an increasingly vocal number of them are threatening to derail her.

While Pelosi is remains the heavy favorite to be her party's choice when House Democrats hold their leadership elections in less than two weeks, the hurdles for her are higher than many expected.

For most of the week, even those Democrats who lobbied the loudest for new leadership were at a loss when asked who they might back as a challenger. On Wednesday, at least one name emerged when Rep. Marcia Fudge, D-Ohio, said she was thinking about jumping in the race.

And on Friday, Fudge said she would announce whether or not she would run after the Thanksgiving break.

Newly elected members joined those who were re-elected in Washington this week for orientation, a gathering that also included numerous receptions and party meetings. Those events provided Pelosi the opportunity to campaign and make her pitch to members. She has met with the congressional caucus, the moderate Problem Solvers Caucus and with new members, and she’s scheduled to meet with the New Democrat Coalition as well.

But it’s also given opponents time to organize against her. Those critics insist that they have the support of more than two dozen members who will not support her, a number they say is enough to put her bid to be speaker in jeopardy.

Pelosi is trying to please a wide array of members, a difficult task considering the caucus just expanded to include members from solidly Republican districts as well as very liberal districts.

Making her position appear more perilous, many members — far more than are likely to oppose her — are withholding their public support and using this intense campaign period to extract concessions from leadership.

After their meeting with Pelosi on Thursday, Congressional Progressive Caucus leaders Mark Pocan, D-Wisc., and Rep. Pramila Jayapal, D-Wash., said they would discuss Pelosi's bid with the members of the caucus.

"We are pleased that Leader Pelosi shares our commitment to ensuring that CPC members are represented proportionally on the key exclusive committees — including Ways and Means, Energy and Commerce, Appropriations, Financial Services and Intelligence," they wrote. "With the talent of the incoming class of new members, we agreed that there should be opportunities not only for seasoned CPC members, but also for our brand new CPC members, many of whom bring particular issue-area expertise."

The Problem Solvers Caucus wants new rules to give committees more power and to make it easier for bipartisan amendments to receive a vote. And the New Dems want the next leader to focus on supporting members from purple and red districts.

“We believe that in order to build a sustainable majority, we need leadership that is focused on fostering a caucus and policy agenda that works for those who won seats to get us in the majority,” said New Democrat Coalition Chair Jim Himes, D-Conn.

There is also a group of members, including Rep.-elect Alexandria Ocasio-Cortez, D-N.Y., who are demanding that climate change be a top priority for the new Congress.

Ocasio-Cortez, after participating in a climate change protest in Pelosi’s office, said that she has spoken with Pelosi about the issue. While she said she has not decided on how she’ll vote for speaker, she said she is encouraged by her discussions with Pelosi.

“She’s been very receptive on this climate issue, and I’m very impressed in how she’s authentically responding to this issue,” Ocasio-Cortez said. “I don’t think it’s a superficial conversation at all. This is really getting to the meat of our discussions as a party, and I’m very grateful for that.”

And others just say they want change, including Rep. Kathleen Rice, D-N.Y., who says she will vote against Pelosi and is looking forward to more candidates jumping in the race.

“It's nothing personal on any of the leaders that we have," Rice told reporters. "They've been great, but they've been there for 16 years and it's time for a new generation of leaders to take over.”

Still, Pelosi is exuding confidence. “I have overwhelming support in my caucus to be speaker of the house,” she said Thursday. “I happen to think at this point I'm the best person for that.”

Pelosi has her supporters. Eleven labor unions, including the AFL-CIO and the United Steelworkers, have announced their support of her. And her office released a letter by two new members who argue that Pelosi is the best choice.

“During this turbulent time in our nation’s history, no one is better prepared to lead a diverse Democratic caucus,” Katie Hill and Mike Levin, both of California, wrote. “Let’s unite. Let’s move forward. Let’s make change happen, together.”

House Democrats have two opportunities to vote for speaker. On Nov. 28, they will gather behind closed doors where individual votes remain secret unless members say publicly how they voted. Any candidate for speaker must get a majority.

There was an effort this week among some of the anti-Pelosi forces to win a rules change so that a speaker candidate would have to get the support of 218 Democrats, making it harder for Pelosi — or any candidate — to win the support of the caucus. The idea came up briefly but went nowhere.

But on the floor, the threshold is 218, or a majority of people who vote for a candidate. That’s where the Pelosi opponents think she’ll have a real problem because Democrats will have no fewer than 233 seats, leaving little margin for Pelosi to have many detractors.

Members can vote "present," however, as a way to fulfill some members’ campaign promise to not support Pelosi, and it also reduces the majority threshold.

CORRECTION (Nov. 16, 2018, 12:35 p.m. ET): A previous version of this article misstated the party affiliation of Rep. Pramila Jayapal of Washington. She is a Democrat, not a Republican.