WASHINGTON (Reuters) -A weekend deal to end the longest U.S. government shutdown in history divided Senate Democrats and angered the party's vocal liberal base, who turned their vitriol on Senate Minority Leader Chuck Schumer for the second time this year.

Schumer and his fellow Democrats in the Senate triggered the shutdown seeking to prevent the expiration of health insurance subsidies for 24 million Americans, a calculated move after the New York lawmaker outraged fellow Democrats in March by agreeing to a deal to avoid a shutdown.

Personally, he held firm on Sunday, voting against the measure to move towards reopening the government. But eight members of his caucus - enough to advance the measure - broke ranks, arguing that President Donald Trump's administration was taking advantage of the situation to undermine needed programs. That fracture led to fresh criticism of the 74-year-old lawmaker's leadership.

"Leadership is about changing and adapting when there is real need, and unless we hear that, we will fail to meet the moment," first-term Senator Elissa Slotkin of Michigan said in a statement.

While the criticism from the left was scathing, only the 45 Democratic senators and two independents who caucus with them have a say on whether Schumer can be removed from his leadership role or defeated in a leadership election that would be held following the November 2026 elections. Schumer is not up for re-election to another six-year Senate term until 2028.

Progressives took a much harsher tone, with the advocacy group "Our Revolution" urging Schumer to resign as minority leader, as did Representative Ro Khanna of California, who said in a statement, "Senator Schumer is no longer effective and should be replaced."

California Governor Gavin Newsom, seen as a contender for the 2028 Democratic presidential nomination, on social media called the compromise "Pathetic. This isn't a deal. It's surrender."

DAYS AFTER ELECTION VICTORIES

The blowback came less than a week after the party celebrated wins in a handful of elections last Tuesday, which saw moderate Democrats clinch dominating wins for governor in Virginia and New Jersey and a democratic socialist elected mayor of New York City. It also reflected the frustrations of a party largely boxed out of power in Washington, where Trump's Republicans control the House of Representatives and Senate.

Schumer, in a speech to the Senate on Monday, said that Democrats succeeded in putting healthcare "at the forefront of people's minds."

"The American people will not forget Donald Trump's cruelty and heartlessness over the past six weeks," he added.

Jon Cowan, president of the centrist think tank Third Way, said in an interview that the attacks on Schumer coming from the left will likely subside.

"Every Democrat and allied interest group is going to end their circular firing squad and aim all of their ammunition at Trump" and at congressional Republicans who are vulnerable to losing their seats in next year's elections, he said.

'BRUTAL BLOW'

Some of Schumer's fellow Senate Democrats tried to refocus the anger on Trump.

While calling the Sunday vote to move forward on reopening the government - a process that will take several days at least - a "brutal blow," Senator Jeff Merkley of Oregon added, "The real villain is Trump and congressional Republicans."

Still there has been pressure building in the party for years for aging leaders to step aside, clearing the way for new blood, particularly after concerns about former President Joe Biden's age played a role in the party's losses in the 2024 election that saw Trump returned to power. Former House Speaker Nancy Pelosi in 2022 gave up her leadership role and last week said she would not seek re-election, bringing her career to a close. 

For months now, Democrats have been fighting to stop significant increases in health insurance premiums with the December 31 expiration of an Affordable Care Act subsidy. Congressional Democrats had refused to allow a government funding bill to pass until their demands for renewing the subsidy were met.

"Caving on a deal that doesn't fix health care is, and always has been, a giant betrayal of the American people," said former Congressional Progressive Caucus Chair Pramila Jayapal of Washington State.

Notably, of the eight Democrats voting yes on Sunday, six are not up for re-election next year and two are retiring, including No. 2 Senate Democrat Dick Durbin.

Durbin said Schumer was disappointed when he told the Democratic leader he would vote to end the shutdown.

"He was a gentleman about it, though he disagreed with me," Durbin told reporters. "I think our friendship is still intact."

The deal faced criticism even from party moderates - including New Jersey Governor-elect Mike Sherrill, who called it "malpractice." 

"Last week we won with a broad coalition after laying out a plan that takes bold action on costs, despite political pressure and people saying it couldn't be done," Sherrill said in a statement. "Voters made it clear: the American people want leadership with a backbone."