WASHINGTON — Speaker Nancy Pelosi, facing deep alarm among moderate Democrats who worry that Senator Bernie Sanders will win their party’s presidential nomination only to cost them control of the House, has begun distancing her caucus from the race for the White House in an effort to insulate her rank and file and preserve the party’s majority.
Ms. Pelosi, the highest-ranking Democrat and the de facto leader of her party, insisted in public and in private on Thursday that Democrats would be united around their nominee no matter who it was — even as she pointedly refused to embrace Mr. Sanders’s agenda, especially Medicare for All, which lacks the votes to pass the House.
When jittery members of her caucus met Thursday afternoon behind closed doors at the Democratic National Committee headquarters to discuss the possibility of a protracted convention fight, one lawmaker joked that the race was so fluid and tumultuous that the speaker herself might wind up as president.
“I like my job — you’re not getting rid of me that easily,” Ms. Pelosi replied teasingly, according to two people who were present. She urged Democrats to “keep our eye on the ball” and focus on winning their own seats and defeating the president. She mocked Mr. Trump’s skin color: “The ball has an orange face,” she said.
But amid the laughter, Ms. Pelosi must manage the anxieties — and political calculations — of the 40 or so House Democrats known as front-liners who flipped Republican seats in 2018, many of them in districts won by Mr. Trump. She is playing the dual role of den mother and general, trying to assuage her members’ fears and keep them focused on their own races, all while staying assiduously neutral in the presidential contest.
“Nancy Pelosi is the ballast of our ship; she is the stabilizing force,” said Representative Andy Levin, a freshman Democrat whose Michigan district includes Macomb County, which Mr. Trump won in 2016.
“The thing that is amazing about her is she sort of knows when to steer and when not to steer,” Mr. Levin added.
Ms. Pelosi’s strategy of distancing Democrats from the presidential race is reminiscent of the one Republicans adopted in 2016 when another populist candidate who sowed fears in the party establishment — Donald J. Trump — emerged as the front-runner in a similarly unruly primary season. The speaker then was Paul D. Ryan, a mainstream conservative Republican who found himself on a collision course with Mr. Trump, whose policy prescriptions stood in stark opposition to party orthodoxy.
“There is a chance that works” for Ms. Pelosi, too, said Brendan Buck, a counselor to Mr. Ryan at the time. “We were able to run a parallel agenda because people looked at Donald Trump as his own person and didn’t necessarily think every Republican is just like Donald Trump.”
But at this point in the 2016 race, few Republicans thought Mr. Trump could actually win the nomination, and hardly any members of Congress had endorsed him. Mr. Trump was clearly an outsider. Mr. Sanders, by contrast, has been in politics for decades and, despite his affiliation as an independent, is a member of the Senate Democratic leadership with relationships across the Capitol.
In addition, the party’s complicated nominating system gives congressional Democrats a say in the process, which individual Republican lawmakers do not have. Every congressional Democrat is a “superdelegate,” which gives them the ability to cast a vote for their favored nominee if no one gets a majority of delegates after all states have conducted their caucuses and primaries.
With so many Democratic candidates in the race, that is a real possibility this year. Mr. Sanders is the only candidate who has said “the person with the most votes should get the nomination.” On Thursday, Ms. Pelosi appeared to push back on that assertion, though she declined to say whether she would urge her fellow Democrats to support a candidate who lacked a majority of pledged delegates at the convention this summer.
“The person who will be nominated will be the person who has a majority plus one,” Ms. Pelosi told reporters at her weekly news conference. “That may happen before they even get to the convention, but we’ll see.”
While Ms. Pelosi has repeatedly called for Democrats to remain unified, she is also pushing them to run on the three-pronged “For the People” agenda — creating good-paying jobs, rooting out corruption and lowering the cost of health care and prescription drugs — that delivered them the majority in 2018.
“We have to win in certain particular areas,” she told reporters Thursday morning, adding, “It is not unusual for a party platform or the candidates for president to have their own agenda that they would put forth, and it’s not unusual for the House of Representatives to have its agenda as well.”
A string of Democrats said in interviews that they believed Mr. Sanders, of Vermont, would be disastrous as a nominee, and that Ms. Pelosi was well aware of their feelings.
“My responsibility is to make sure that those we elected last time return to Congress, keep the majority and add to our numbers,” Ms. Pelosi told reporters. “The presidential is its own race, and contrary to what you may be hearing or writing, we are all unified. Whoever the nominee is of our party, we will wholeheartedly support.”
She said Democrats would win again with “a message of a bold progressive agenda that is mainstream and nonmenacing.” But she brushed aside a question about whether Mr. Sanders’s agenda fit that description and has given little hint, even to her closest aides and allies, of whom she favors in the presidential race — or whether she favors anyone at all.
“She’s not telling us anything one way or another,” said Representative Donna E. Shalala, a freshman Democrat from Florida. She said she had let Ms. Pelosi and other leaders know that Mr. Sanders was “unacceptable to me and to my constituents,” in part because of his recent comments praising literacy programs in Cuba during the dictatorship of Fidel Castro.
“He’s a socialist,” Ms. Shalala said in a brief interview, “and he doesn’t understand the tyranny of these Latin American countries.”
Another centrist, Representative Tom Malinowski, a freshman from New Jersey, said he had endorsed former Vice President Joseph R. Biden Jr. and feared that a Sanders nomination would mean a crushing loss for Democrats in November.
“Why we would risk this extraordinary opportunity by nominating somebody who has a tendency to divide our own side is beyond me,” he said.
Republicans have already begun working hard to convince voters that there is no distinction between Mr. Sanders and Democratic members of Congress, despite the fact that fewer than 10 House Democrats have endorsed the Vermont senator and many have long records of disagreement with him.
House Republicans tried on Thursday to force a vote on a resolution condemning Mr. Sanders’s approving remarks about Fidel Castro in an attempt to squeeze moderate Democrats like Ms. Shalala who represent many Cuban-American constituents.
Michael McAdams, a spokesman for the National Republican Congressional Committee, was more direct. He asserted on Thursday that Mr. Malinowski was “all in on Bernie Sanders’s socialist agenda” based on his press statement that he would support Mr. Sanders if he was the party nominee.
When Ms. Pelosi was asked on Wednesday if she felt comfortable with Mr. Sanders as the nominee, she offered a succinct reply: “Yes.”
Mr. Sanders’s progressive backers have grabbed onto the comments as perhaps the best argument for uneasy colleagues.
“Nancy sent a pretty clear message yesterday of unity, saying she is comfortable with Bernie being the nominee,” Representative Mark Pocan, Democrat of Wisconsin and a vocal supporter of Mr. Sanders, said in an interview. “People should be comfortable if Nancy is. I think a few may just be overthinking or not thinking.”