As Judge Neil Gorsuch breezed through the home stretch of confirmation hearings Thursday, Senate Democrats' struck a defiant public posture while looking behind the scenes for a possible deal that could set up the next Supreme Court nomination battle.

Gorsuch, the 49-year-old 10th Circuit U.S. Court of Appeals judge, came through three days of grueling hearings before the Senate Judiciary Committee largely unscathed. With confirmation by the full Senate looming, sources told Fox News Democrats were weighing a number of strategic options -- including a stand down in exchange for a GOP pledge to not go "nuclear" on a future nomination by President Trump -- despite their public statements.

"He will have to earn 60 votes for confirmation,” Senate Minority Leader Chuck Schumer, D-N.Y., said Thursday, referring to the threshold for ending a filibuster and preventing the minority party from blocking the confirmation.

But after even Gorsuch's critics conceded the squeaky-clean, Harvard-trained jurist deftly parried his Democratic critics' questions and came off as likeable and intelligent, Schumer's vow is likely more bargaining stance than threat, sources said. Gorsuch was nominated January 31 to fill the seat of the late Justice Antonin Scalia. Confirmation hearings in the Senate Judiciary Committee will conclude, but the nominee finished his testimony on Wednesday.

Republicans, who hold 52 seats in the upper chamber, have the option of changing Senate rules so that a filibuster can be ended with a simple majority vote. Democrats, when in the majority during the Obama administration, made the rules change effective for all non-Supreme Court nominations.

Democrats are leery of pressing the ongoing confirmation process to the point Republicans invoke the so-called nuclear option, as it would make a subsequent Trump nomination a fait accompli. But on Tuesday, Senate Majority Leader Mitch McConnell expressed doubt that any Democrats would vote to confirm Gorsuch, a strong signal the Kentucky Republican is ready to change the rule.

“It does sound like he’s laying the groundwork for the nuclear option,” Senate Minority Whip Richard Durbin said of McConnell. “Let’s wait and see how this evolves.”

Trump Adviser for the Supreme Court Leonard Leo scoffed at the idea Republicans could be pressured into withholding the nuclear option in exchange for Gorsuch's confirmation.

“This absurd ‘deal’ would prolong an environment in which Democrat Supreme Court nominees get up or down simple majority votes and Republican nominees get filibustered -- that’s not a deal, it’s a unilateral disarmament,” Leo said.

Democrats from states that supported Trump in the presidential election could find themselves under pressure from voters to not appear obstructionist, especially to an appealing nominee. But Sen. Bob Casey, D-Pa., who is up for re-election in 2018, said Thursday he would not vote for Gorsuch.

“After considering his nomination seriously and without pre-judgment, and mindful of the awesome responsibility of passing judgments on nominees to the highest court in the nation, I do not believe Judge Gorsuch’s judicial approach will ensure fairness for workers and families in Pennsylvania,” Casey said. “I have concluded that Judge Gorsuch is not the right choice to fulfill this commitment -- I will not support his nomination.”

Judge Gorsuch is not the right choice to fulfill this commitment. https://t.co/cn3FVySa0B pic.twitter.com/8AnaaLTFPJ — Senator Bob Casey (@SenBobCasey) March 23, 2017

The vote could take place as early as Monday, but Democrats are expected to ask for a one-week delay, pushing the Committee vote to April 3, and then immediately to the Senate floor.

Top Senate Republicans said they would do what they needed to do to get Gorsuch through to the bench.

And McConnell is confident.

“We’ll confirm him before we leave for the April recess.”

Fox News' William Mears contributed to this report.