WASHINGTON (Reuters) – Democrats on Monday amassed enough support to block a U.S. Senate confirmation vote on President Donald Trump’s Supreme Court nominee, Neil Gorsuch, but Republicans vowed to change the Senate rules to ensure the conservative judge gets the lifetime job.

The Senate Judiciary Committee voted 11-9 along party lines to send Gorsuch’s nomination to the full Senate, setting up a political showdown between Trump’s fellow Republicans and the opposition Democrats that appears likely to trigger a change in long-standing Senate rules to allow his confirmation.

Before the vote, Senator Christopher Coons, a member of the panel, became the 41st Democrat to announce support for a procedural hurdle called a filibuster requiring a super-majority of 60 votes in the 100-seat Senate to allow a confirmation vote.

The Senate’s Republican leaders insist Gorsuch will be confirmed on the Senate floor on Friday regardless of what the Democrats do. Republicans hold a 52-48 majority in the Senate.

In the face of the filibuster, Senate Majority Leader Mitch McConnell would be expected to force a confirmation vote by having the Senate change its rules and allow for a simple majority vote for confirmation of Supreme Court justices, a move sometimes called the “nuclear option” that Trump has urged.

Judiciary Committee Republicans blasted Democrats for pursuing what they called the first “partisan filibuster” of a Supreme Court nominee – there was a successful bipartisan filibuster five decades ago against a Democratic president’s nominee – and said it would come to naught because of the threatened rule change.

But it was Senate Republicans who last year refused to even consider Democratic former President Barack Obama’s nomination of appellate judge Merrick Garland to fill the same high court vacancy that Trump has selected Gorsuch to fill.

“Democrats, including me, are still furious at the way Judge Merrick Garland was treated last year. But the traditions and principles that have defined the Senate are crumbling and we are poised to hasten that destruction this week,” Coons said.

Coons left room for a compromise, in which Democrats would allow the vote to go ahead in return for Republicans agreeing to a 60-vote threshold for the next Supreme Court vacancy.

“So for my part, I hope and pray that we can yet find a way together to find a solution,” Coons added.

Senate confirmation of Gorsuch, 49, would restore the nine-seat high court’s conservative majority, fulfilling one of Trump’s top campaign promises. Trump in January nominated Gorsuch, a conservative appeals court judge from Colorado, to the lifetime job as a justice. He could be expected to serve for decades.

Gorsuch was nominated to fill a vacancy created by the February 2016 death of conservative Justice Antonin Scalia.

Republicans control the White House and Congress for the first time in a decade. The inability of Senate Republicans to coax enough Democratic support to avoid the “nuclear option” reflected the intense partisan divide in Washington and the Trump administration’s failure to win the cooperation of the opposition party.

White House spokesman Sean Spicer accused Democrats of partisan obstruction that sets “a very dangerous precedent” and told a briefing that “we’re obviously disappointed that the overwhelming majority of them are still playing politics with the nation’s highest court.” Spicer said the decision on the “nuclear option” rested with McConnell.

The committee’s chairman, Republican Chuck Grassley, defended Gorsuch as a mainstream jurist worthy of confirmation. Committee Republican John Kennedy called Gorsuch “a legal rock star” and a “thoroughbred.”

Democratic Senators Dianne Feinstein, the committee’s top Democrat, and Mark Warner, not a member of the panel, also announced opposition to Gorsuch on Monday and support for a filibuster.

The actual confirmation vote would be by a simple majority if the filibuster is stopped. To date, three Democrats have come out in support of Gorsuch, and the Republicans would have needed to secure eight Democratic votes to kill a Gorsuch filibuster.

With the failure of Republican healthcare legislation in Congress and with courts blocking the president’s ban on people from several Muslim-majority nations from entering the United States, winning confirmation for Gorsuch has taken on even more importance for Trump.

Democrats have accused Gorsuch of being insufficiently independent of Trump, evading questions on key Supreme Court rulings of the past including on abortion and political spending, and favoring corporate interests over ordinary Americans.

Democratic Senator Michael Bennet, who represents the nominee’s home state of Colorado and introduced the nominee during his confirmation hearing, said he would oppose the Gorsuch filibuster effort but did not take a position on whether to vote in favor of the judge.

Feinstein said this was not a “routine nomination,” noting what happened to Garland.

“There was simply no reason that the nomination of Judge Garland could not proceed, other than to deny the then-president of the United States, President Barack Obama, the ability to fill the seat,” Feinstein said.

Feinstein criticized Gorsuch’s rulings against a fired truck driver and an autistic child and faulted his actions as a lawyer in Republican former President George W. Bush’s Justice Department regarding detainee interrogation techniques critics called torture.

Feinstein also said she was disturbed by the millions of dollars of “dark money” from anonymous donors backing advertising and political advocacy by conservative groups to help Gorsuch win confirmation.

The 60-vote super-majority threshold that gives the minority party power to hold up the majority party has over the decades forced the Senate to try to achieve bipartisanship in legislation and in presidential appointments.

Senator Lindsey Graham, a Republican committee member, expressed regret that his party would be forced to change the Senate rules and said the “damage done to the Senate’s going to be real.”

“If we have to, we will change the rules, and it looks like we’re going to have to. I hate that. I really, really do,” Graham said.

Senator Orrin Hatch, a committee Republican, said Democrats were acting under pressure from “the radical left.”

While Gorsuch’s opponents would fight a Senate rule change, it was the Democrats who in 2013 changed the Senate rules to limit filibusters after Republicans used the procedure against Obama’s appeals court nominees. The Senate, then led by Democrats, barred filibusters for executive branch nominees and federal judges aside from Supreme Court justices. Even if Republicans do change the rules, legislation, as opposed to appointments, would still need to meet a 60-vote threshold.

(Reporting by Lawrence Hurley; Additional reporting by Susan Heavey, Mohammad Zargham, Tim Ahmann and Doina Chiacu; Editing by Will Dunham)