Senate Majority Leader Mitch McConnell guaranteed Tuesday that there will not be an effort to change the debate rules surrounding legislation, even as senators are hurtling towards a rule change on Supreme Court nominees.

“There’s no sentiment to change the legislative filibuster,” the Kentucky Republican told reporters at his weekly press conference. Asked if he was committing to not changing the rules to end debate on legislation while he is the GOP leader, McConnell said, “Correct.”

Requiring 60 votes to invoke cloture, or end debate, on legislation is a unique characteristic of the Senate, which has the effect of requiring some bipartisan support or agreement to move legislation forward. Senators often argue that changing the protocol for cutting off debate — the cloture rule — would fundamentally alter the nature of the chamber.

McConnell has signaled he is prepared to change the cloture rule relating to Supreme Court nominations so that President Donald Trump’s high court nominee, Judge Neil Gorsuch, can advance by a simple majority vote. This week McConnell is expected to employ the so-called nuclear option and effectively change the Senate rules by a majority vote, rather than two-thirds of the senators who are present and voting.

But Sen. John McCain, who had pushed against previous uses of the nuclear option, was not terribly optimistic about the legislative filibuster’s future.

“I can’t say with confidence, and I’m afraid we’re on a slippery slope,” the Arizona Republican said. “Benjamin Franklin somewhere is turning over because he’s the one that advocated for the role of the Senate.”

McCain said without the supermajority requirements for legislation, there might as well be a unicameral legislature.

“Why should we be bicameral if they’re all voting, all operating under the same rules?” he said.

Still, McCain was resigned that the threshold for ending debate on Supreme Court nominees would be lowered from 60 to a majority. Democrats, when they were in the majority in 2013, pushed through a Senate rules change so that only a majority vote is required to end debate on Cabinet nominees and federal judges on the district and circuit levels. 

McConnell said he was confident that the majority of Republicans would support changing the rules to lower the threshold for high court nominees.

“If the rule were changed, it would apply to future Supreme Court nominees,” McConnell said, though he argued that doing so would return the Senate to its previous practice of approving Supreme Court nominees by a majority vote. 

Senate Democrats have secured enough votes to filibuster Gorsuch’s nomination. But they have argued that changing the rules is damaging to the Senate, and that nominees to the high court should meet a 60 vote threshold.

“It’s up to [Republicans] not to invoke the nuclear option,” Senate Minority Leader Charles E. Schumer told reporters Tuesday at his weekly press conference. “It will symbolize to the American people that Mitch McConnell will virtually do anything, anything, even hurting the Senate, to get his way on the court.”

Meanwhile, even as the Senate is focused on the Supreme Court, House Republicans are attempting to revive the effort to repeal and replace the 2010 health care law. But that doesn’t mean senators are highly engaged on the matter. 

Vice President Mike Pence has been meeting with House lawmakers on the issue, but it did not appear that he had a lengthy health care discussion with GOP senators when he attended their weekly policy lunch on Tuesday. 

Senate Majority Whip John Cornyn signaled that the health care discussions would remain a project of the House and the Trump administration.

“I think it’s really up to the House to figure it out, and then we’ll worry about it after they send us a bill,” the Texas Republican told Roll Call.