WASHINGTON — Senate Republicans invoked the “nuclear option” Thursday, overturning the body’s rules so Neil Gorsuch could be confirmed to the Supreme Court with a simple majority vote.

The vote — entirely along party lines — was 52 to make the change and 48 against.

Senate Majority Leader Mitch McConnell said the change — from 60 to 51 votes — was necessary to break a Democratic filibuster intended to block the Colorado appellate judge.

“This will be the first — and last — partisan filibuster of a Supreme Court nomination,” McConnell said of the history-making step.

“The nuclear option means the end of a long history of consensus on Supreme Court nominations,” griped Senate Minority Leader Charles Schumer.

The extreme move was teed up shortly after 11:30 a.m. when the Senate voted 55-45 to end debate, failing to advance President Trump’s first high court nominee with the minimum 60 votes necessary.

Four Democrats joined Republicans: Sens. Joe Manchin of West Virginia, Heidi Heitkamp of North Dakota, Joe Donnelly of Indiana and Michael Bennet of Colorado.

Falling short of the 60 votes needed, McConnell moved to change the rules for Supreme Court nominees to 51 votes.

“Our Democratic colleagues have done something today that is unprecedented in the history of the Senate,” McConnell said. “Unfortunately, it has brought us to this point. We need to restore the norms and traditions of the Senate and get past this unprecedented, partisan filibuster.”

Republicans blamed the “radical move” on the Democrats’ unwillingness to accept Trump as the president.

“This isn’t really about the nominee anyway,” McConnell said before the vote. “The opposition to this particular nominee is more about the man that nominated him and the party he represents than the nominee himself.”

Schumer said the real extreme option was when McConnell refused to even allow President Obama’s nominee, Merrick Garland, a hearing. The blame falls on Republicans’ shoulders, he said.

“We believe what Republicans did to Merrick Garland is worse than a filibuster,” Schumer said. “…These past few weeks, we Democrats have given Judge Gorsuch a fair process, something Merrick Garland was denied.”

Gorsuch heads to a final vote Friday in the Senate, where he’s expected to pass with a majority of votes.

He’d filled the vacancy left by the death of conservative Justice Antonin Scalia in February 2016.

Both parties bemoaned the breakdown of the Senate and worried that the elimination of the 60-vote threshold will lead to more partisan justices.

Democrats under Sen. Harry Reid deployed the nuclear option in November 2013 under Obama to get his lower-court nominations approved but had maintained the 60-vote rule for Supreme Court nominees.

In a last-ditch effort to avoid going nuclear, Schumer put forward a motion to postpone the nomination vote to April 24 — after the two-week Easter recess — to allow both sides and Trump to chart a path forward. That vote failed 48-52 in a party-line division.

“In a post-nuclear world, if the Senate and the presidency are in the hands of the same party, there’s no incentive to even speak to the Senate minority,” Schumer said. “That’s a recipe for more conflict and bad blood between the parties, not less.”