(Jenny Starrs/The Washington Post)

The Senate plowed Tuesday toward a historic and bitter showdown over President Trump’s Supreme Court nominee, with a parade of lawmakers taking to the Senate floor to deliver politically charged speeches for and against the president’s pick as a final vote neared.

There was no sign of compromise as the chamber formally opened debate on Judge Neil Gorsuch, who Senate Majority Leader Mitch McConnell (R-Ky.) predicted will be confirmed on Friday before senators leave town for the two-week Easter recess.

In a speech on the Senate floor, McConnell faulted Democrats for “hurtling toward the abyss” and “trying to take the Senate with them.” He urged them to “reconsider” their tactics.

“It appears as if cloture will not be invoked, but we’ll find out on Thursday,” McConnell later told reporters, referring to an expected Democratic blockade of the federal appeals court judge. “But either way, we’ll be moving toward confirming Judge Gorsuch.”

Only four Democrats have vowed they will side with Republicans to break that blockade and move to consider Gorsuch on the Senate floor. One staunch Gorsuch critic, Sen. Jeff Merkley (D-Ore.), took to the Senate floor Tuesday night to launch a marathon speech against him. Merkley’s office said he planned “to hold the floor and refuse to yield for as long as he is able to continue speaking.”

Sen. John McCain (R-Ariz.), who said Tuesday he would not try to broker any dispute involving judicial nominees, speaks to journalists at the U.S. Capitol on March 28. (Melina Mara/The Washington Post)

The overall Democratic obstruction is expected to compel GOP leaders to eliminate a 60-vote requirement for Supreme Court nominees and allow confirmation of Gorsuch with a simple majority vote.

The partisan standoff underscores the sharp polarization that has seized Congress less than three months into Trump’s presidency. Senate Democrats angered by Trump’s policies — and McConnell’s refusal to consider Merrick Garland, President Barack Obama’s Supreme Court nominee last year — have united against Gorsuch, clinching enough votes to block him earlier this week.

It also heralds a potentially more contentious climate in the Senate, which traditionally has allowed the minority party to exert a powerful voice in debate over key nominations and legislation — unlike in the House. Senate Democrats changed the rules in 2013 to permit executive-branch nominees and federal judges to be approved by a simple majority, with the critical exception of Supreme Court selections.

But doing away with the 60-vote barrier would eliminate the minority party’s historic influence over who the president nominates to the high court and significantly decrease its ability to help exercise a check on the executive branch.

“There’s a reason they call it the ‘nuclear option,’ and that is that there’s fallout. And this fallout will be dangerously and perhaps disastrously radioactive for the Senate in years to come,” said Sen. Richard Blumenthal (D-Conn.).

The nuclear option — in this case, allowing high court nominees to be approved by a simple majority — may also further poison relations between Democrats and Republicans as each side is embittered by the other’s behavior, from the GOP’s move to block any consideration of Garland in 2016 to the Democratic blockade of Gorsuch now. That could have a practical impact on Trump’s agenda, such as passing a complex tax package, health-care legislation and an infrastructure plan.

Confirmations for the sitting Supreme Court justices were not nearly as partisan as Judge Gorsuch’s

McConnell said that while he is prepared to deploy the nuclear option to overcome Democratic resistance to Gorsuch, he vowed not to end the 60-vote threshold on legislation while he is majority leader, maintaining what is known on Capitol Hill as the filibuster as it pertains to making laws.

“There’s no sentiment to change the legislative filibuster,” he said.

Senate Democrats said the only way they will end their resistance is if Trump submits a new nominee. They portrayed Gorsuch as outside the mainstream and expressed doubts that he has sufficiently demonstrated his independence from Trump.

“If Senator McConnell is willing to be reasonable and cooperate in a bipartisan way, we can avoid the nuclear option,” said Senate Minority Leader Charles E. Schumer (D-N.Y.).

As Democrats and Republicans took turns on the Senate floor on Tuesday, they delivered sharply contrasting speeches. Democrats repeatedly brought up Garland, casting Gorsuch as beholden to wealthy corporate interests and not average Americans. Democrats expressed concern about confirming Trump’s nominee at a time when ties between his team and Russia have come under heavy scrutiny.

“I’ll be honest,” said Sen. Elizabeth Warren (D-Mass.). “I think it is crazy that we are considering confirming a lifetime Trump nominee to the Supreme Court at a moment when the president’s campaign is under the cloud of an active, ongoing FBI counterintelligence investigation that could result in indictments and appeals that will go all the way to the Supreme Court so that Trump’s nominee could be the deciding vote on whether Trump or his supporters broke the law and will be held accountable. That is nuts.”

Republicans portrayed Gorsuch as a more-than-qualified and mainstream judge with sterling career credentials and accused Democrats of caving to their political base.

“Their base demands total war, total obstruction, and they are begrudgingly bowing to this demand. Unfortunately for them, it has proven difficult to invent attacks against an obviously well-qualified judge,” said Sen. Ted Cruz (R-Tex.).

There were no signs, however, that senators were making serious moves on Tuesday to avoid the impasse. Signaling that any hopes of a compromise are probably dead, Sen. John McCain (R-Ariz.), who successfully brokered past disputes on judicial nominees, thanks to his close relationship with several Democrats, said that this time he is done trying.

McCain, who was part of a 2005 agreement among 14 senators of both parties to allow the confirmation of several of former president George W. Bush’s federal court nominees without changing the rules, said talks between Democrats and Republicans in the past few days “didn’t go anywhere.” He declined to specify areas of disagreement.

Meanwhile, the resistance against Gorsuch grew. Sen. Angus King of Maine, an independent who caucuses with the Democrats, announced he would join the Democrats’ blockade.

In a written statement explaining his decision to oppose Gorsuch, King accused the judge of providing answers to questions in his confirmation hearings before the Senate Judiciary Committee that seemed “at best, increasingly evasive, and, at worst, simply not forthright.”

“If I am opposed to this nomination, it seems logical to oppose cloture because under the current rules, this would defeat the nomination,” King said.

In a sign that at least some senators still want to avoid the showdown, Sen. Christopher A. Coons (D-Del.) said that even though he plans to oppose Gorsuch and support the Democratic barricade, he is willing to work on an agreement that would stave off changes to how the Senate confirms Supreme Court nominees.

“There are Democrats and Republicans who I hope will be talking this week, in the next two days, to see if we could find some path forward where we preserve the filibuster,” Coons said in a CNN interview.

Sen. Orrin G. Hatch (R-Utah), a senior member of the Judiciary Committee, said that he had been discussing a potential compromise with Democrats as recently as Monday but admitted “I haven’t made a real push” to reach an agreement.

Plans for a Democratic filibuster “are stupid. I think it’s a big mistake,” Hatch added.

All Republicans are expected to vote to confirm Gorsuch. Only a few Democrats will not stand in his way.

Democratic Sens. Joe Donnelly (Ind.), Heidi Heitkamp (N.D.) and Joe Manchin III (W.Va.) — all of whom are up for reelection in states won by Trump — say they plan to support Gorsuch. Sen. Michael F. Bennet (D-Colo.), who represents Gorsuch’s home state, says he won’t support the filibuster but has yet to signal whether he would vote to confirm Gorsuch on the floor.

The four were the only Democrats who joined with Republicans in the 55-to-44 vote to move ahead with debate on Gorsuch’s nomination Tuesday.

A single-party filibuster has never successfully blocked a Supreme Court nomination. A bipartisan coalition used the procedural vote to defeat Abe Fortas’s 1968 nomination to be chief justice.

For weeks, Republicans have warned that they will not hesitate to change the chamber’s rules to confirm the 49-year-old federal appeals court judge if Democrats block him. A rules change will require majority support.

Asked Tuesday if he is confident he has the votes to make that change, McConnell replied simply: “Yes.”