WASHINGTON — Sen. John Cornyn, R-Texas, reversed himself on the Senate filibuster Wednesday after years of unflinching support for the 60-vote threshold to pass most bills.

Now, locked in a competitive Republican runoff for his Senate seat and eyeing President Donald Trump’s endorsement, Cornyn says he’ll support “whatever changes to Senate rules that may prove necessary” to pass the SAVE America Act, a sweeping election overhaul bill that Trump has called his No. 1 priority.

Cornyn’s comments are part of an op-ed he wrote in the New York Post published Wednesday, titled: “Why the SAVE Act matters more than the filibuster.”

The legislation would impose proof-of-citizenship requirements to register to vote, photo ID to cast a ballot in person or by mail and require states to run voter rolls through a federal database kept by the Department of Homeland Security.

Cornyn supports the bill, but his GOP runoff opponent, Texas Attorney General Ken Paxton, has aligned with Trump in calling for abolition of the filibuster to pass the bill and criticized Cornyn for refusing to take the same stance.

NBC News reported Tuesday that Trump had seemed ready to endorse Cornyn in the race just one week ago, but that the president’s decision is now in “a holding pattern” as Trump emphasizes that Congress must do everything in its power to pass the SAVE America Act.

Cornyn denied Wednesday that he shifted his position on the filibuster to win Trump’s endorsement, telling NBC News: “I would say that’s not true.”

The legislation has passed the House but faces a tough path to 60 votes in the Senate, where Democrats have promised to filibuster it. Noncitizen voting is already illegal and very rare, and Trump has now asked Congress to add other provisions to the bill that would ban transgender people from women’s and girls’ sports.

“After careful consideration, I support whatever changes to Senate rules that may prove necessary for us to get the SAVE America Act and homeland security funding past the Democrats’ obstruction, through the Senate, and on the president’s desk for his signature,” Cornyn wrote in his op-ed.

“This could be a ‘talking filibuster‘ that removes the obstructionists’ free pass and makes them defend their indefensible views on the Senate floor, or it could be a different reform,” Cornyn added.

But when Democrats floated changes to the filibuster in the past, Cornyn strenuously defended the 60-vote threshold, like in early 2022 when Democrats sought to pass their own election overhaul bill, called the Freedom To Vote Act.

“Power is fleeting, and at some point the shoe will always be on the other foot,” Cornyn said at the time, in January 2022. “Liberal activists may like the idea of nuking the filibuster today, but they’ll soon find themselves ruing the day their party broke the Senate.”

He said in another speech that same month, “Not only are our colleagues trying to seize the authority given under the Constitution to the states to manage their own elections, they’re willing to take a wrecking ball to the United States Senate itself and, particularly, the Senate rules.”

And he defended it on Fox News in 2022. “That’s what the filibuster does. It requires us to work together,” Cornyn said.

Cornyn addressed his past defense of the filibuster in Wednesday’s op-ed. “I spent years defending the filibuster because the 60-vote threshold was a net benefit to Texas and our nation,” he wrote. “Before moderate Democrats went extinct, the rules worked. … The Democrats’ recklessness and radicalism have changed the landscape.”

Asked specifically about his past statement that changing the filibuster would “take a wrecking ball” to Senate rules on Wednesday, Cornyn replied: “I said I’d be open to reforms.”

When asked follow-up questions, Cornyn put his hand in front of NBC News’ camera and said, “Go away.”

Senate Majority Leader John Thune, R-S.D., meanwhile, has repeatedly said that there are not enough votes in the Senate to undo the filibuster or pass the bill.

Thune told reporters Tuesday that he will bring the SAVE America Act to the floor but that Democrats will vote it down. “I can guarantee the debate. I can guarantee a vote. I just can’t guarantee an outcome,” he said.