Many Democratic lawmakers continued to express deep frustration at Senator Chuck Schumer on Sunday for having broken with most of his party to allow a Republican spending bill to pass, as the Democratic base increasingly demands stauncher resistance to President Trump’s far-reaching agenda.

Mr. Schumer, a New York Democrat and the Senate minority leader, joined nine other Democrats in allowing the bill to come to a vote, which averted a government shutdown. It was an abrupt reversal from Wednesday, when he said he would oppose the bill.

Explaining his sudden shift in position, Mr. Schumer argued that a shutdown would empower Mr. Trump and Elon Musk’s Department of Government Efficiency. “A shutdown would shut down all government agencies, and it would solely be up to Trump and DOGE and Musk what to open again, because they could determine what was essential,” he told The New York Times in an interview. “So their goal of decimating the whole federal government, of cutting agency after agency after agency, would occur under a shutdown.”

But to critics within his own party, he had squandered the leverage provided by the standoff to negotiate a bipartisan spending bill that would reclaim some of Congress’s power.

“He is absolutely wrong,” Representative Jasmine Crockett, Democrat of Texas, told CNN on Sunday. “The idea that Chuck Schumer is the only one that’s got a brain in the room and the only one that can think through all of the pros and cons is absolutely ridiculous.”

The stream of criticism that Mr. Schumer has faced since his vote comes as the Democratic Party is divided on how best to oppose Mr. Trump’s agenda while facing dismal polling numbers. An NBC poll released on Sunday showed that just 27 percent of voters had positive views of the party, while a majority of its base expressed disappointment at the Democrats’ fractured response.

Ms. Crockett has called on her Senate colleagues to consider ousting Mr. Schumer as minority leader, suggesting that “a younger, fresher leadership” is what “many Americans may be looking for.”

Representative James E. Clyburn, Democrat of South Carolina, told MSNBC that the House minority leader, Representative Hakeem Jeffries of New York, “got blindsided” by Mr. Schumer. House Democrats — all but one opposed the bill — had voted against giving Mr. Trump “a blank check,” Mr. Clyburn said. On Friday, Mr. Jeffries dodged repeated questions on whether he still supported Mr. Schumer as the leader of Senate Democrats.

Another House Democrat, Representative Debbie Dingell of Michigan, was a little more understanding, saying that Mr. Schumer had “sent out mixed signals.” But she stressed that even the American Federation of Government Employees, the largest labor union representing federal workers, whose members would be furloughed during a government shutdown, opposed the stopgap bill.

“People are scared, and they want us to do something,” Ms. Dingell said on CBS. “They want to see Democrats fighting back.”

Senator Chris Murphy, Democrat of Connecticut, did not denounce Mr. Schumer but pleaded for a change in tactics and for a more steadfast resistance against the Trump administration.

“The way the president is acting using law enforcement to target dissidents, harassing TV stations and radio stations that criticize him, endorsing political violence, puts our democracy at immediate risk,” Mr. Murphy said on NBC. Over the past few weeks, Mr. Trump has revoked security clearances of lawyers who argued against him, dismantled congressionally funded news agencies and pardoned those convicted of attacking the Capitol on Jan. 6, 2021.

Mr. Murphy added, “If you are a Democrat in the Senate or in the House you have to start acting with urgency.”

Prominent House Democrats, including Representative Nancy Pelosi, had pressed their Senate colleagues to block the bill. But more than a handful of Democratic senators joined Mr. Schumer in helping Republicans bring the bill to a vote: Dick Durbin of Illinois, Brian Schatz of Hawaii, Catherine Cortez Masto of Nevada, John Fetterman of Pennsylvania, Kirsten Gillibrand of New York and Maggie Hassan of New Hampshire, as well as two who have announced plans to retire, Gary Peters of Michigan and Jeanne Shaheen of New Hampshire. Senator Angus King, the Maine independent who caucuses with Democrats, also voted yes.

Some Democrats, including Representatives Jake Auchincloss of Massachusetts and Haley Stevens of Michigan, refrained from openly criticizing Mr. Schumer’s shift. They said Democratic infighting after the bill’s passage would only emphasize the divisions within the party. They warned that it would also draw voters’ attention away from Trump trade policies that have dampened the stock market and imbued uncertainty into the broader economy — developments that Democrats said could play to their advantage.

Ashley Etienne, a former communications director for Vice President Kamala Harris, told CNN that Democrats should not save Mr. Trump and Republicans from themselves. “Get out of the way,” she said. “Donald Trump said he was better for the economy. Let him prove it.”