WASHINGTON >> A Democratic senator yielded the Senate floor today morning after talking through the night to highlight his party’s opposition to President Donald Trump’s Supreme Court nominee, Neil Gorsuch.

But the theatrics from Oregon Sen. Jeff Merkley could not change the outcome, with Senate Majority Leader Mitch McConnell and his Republicans prepared to steamroll Senate rules in order to eliminate Democrats’ ability to block Gorsuch with a filibuster.

Merkley spoke through the night, for more than 15 hours, finally stopping midmorning today with a final plea to colleagues to oppose Gorsuch, a federal appeals court judge from Denver.

“This is an extreme nominee from the far right who doesn’t believe in the fundamental vision of ‘We the People’ and makes decision after decision through tortured, twisted, contrived arguments defined for the powerful over the people, and that is unacceptable,” Merkley said.

Following Merkley on the floor, McConnell ridiculed the opposition from Democrats.

“Democrats would filibuster Ruth Bader Ginsburg if President Donald Trump nominated her,” McConnell said, naming one of the more liberal sitting justices. “There is simply no principled reason to oppose this exceptional, exceptional Supreme Court nominee.”

The Senate is now pointed to a showdown Thursday, when Democrats will try to block Gorsuch’s confirmation, but McConnell will then unilaterally change Senate rules to lower the threshold required to advance Supreme Court nominees from 60 votes to a simple majority in the 100-member Senate.

Democrats blamed Republicans for pushing them to attempt a nearly unheard-of filibuster of a qualified Supreme Court pick. Forty-four Democrats intend to vote against proceeding to final confirmation on Gorsuch, which would be enough to block his nomination under the Senate’s existing parliamentary rules that require 60 votes to advance a nomination.

But McConnell and Republicans say the Democrats’ obstruction leaves them with no choice. Asked Tuesday if he has the votes for the rules change, given misgivings voiced by many Republicans, McConnell answered simply, “Yes.”

Democrats tried mightily to keep the focus on Republicans’ plans to change Senate rules, rather than on their own plans to obstruct a nominee who would likely have gotten onto the court easily with no filibuster in earlier, less contentious political times.

Senate Minority Leader Chuck Schumer of New York said, “Senator McConnell would have the world believe that his hands are tied. That the only option after Judge Gorsuch doesn’t earn 60 votes is to break the rules, to change the rules. That could not be further from the truth.”

In fact, a Senate rules change does appear to be the lone route that Republicans have to put Gorsuch on the court. And despite claims from Schumer and others that Trump and Republicans could go back to the drawing board and come up with a more “mainstream” nominee, it seems unlikely that any nominee produced by Trump would win Democrats’ approval.

On Tuesday evening McConnell officially filed a “cloture” motion, the procedural step designed to end debate on a nomination and bring it to a final vote. That started the clock toward a showdown on Thursday, when Democrats are expected to try to block Gorsuch, at which point Republicans would respond by enacting the rules change. The change is known on Capitol Hill as the “nuclear option” because of the potential repercussions for the Senate and the court.

For the Senate, it would mean that future Supreme Court nominees could get on the court without bipartisan support, potentially leading to a more ideologically polarized court. More immediately, Gorsuch’s confirmation to fill the vacancy on the court created by Scalia’s death would restore the conservative voting majority that existed before Scalia’s death and could persist or grow for years to come.

Lawmakers of both parties bemoaned the further erosion of their traditions of bipartisanship and consensus. Some were already predicting that they would end up eliminating the 60-vote requirement for legislation, as well as nominations. But McConnell pledged Tuesday that this would not happen on his watch.

Gorsuch now counts 55 supporters in the Senate: the 52 Republicans including McConnell, along with three moderate Democrats from states that President Donald Trump won last November — Joe Manchin of West Virginia, Heidi Heitkamp of North Dakota and Joe Donnelly of Indiana. A fourth Senate Democrat, Michael Bennet from Gorsuch’s home state of Colorado, has said he will not join in the filibuster against Gorsuch but has not said how he will vote on final passage.

Gorsuch, 49, is a 10-year veteran of a federal appeals court in Denver, where he’s compiled a highly conservative record that’s led Democrats to complain that he too often sides with corporations without regard to the humanity of the plaintiffs before him.

Associated Press writer Mary Clare Jalonick contributed to this report.