Senate Republicans are poised "to go nuclear" and blow up Senate rules to seat Judge Neil Gorsuch on the Supreme Court and appear to have the votes to follow through on their threat now that a Democratic-led filibuster appears inevitable.

Sen. John Cornyn, R-Texas, the second-highest ranking GOP leader and top vote-counter, said Monday that Gorsuch would be confirmed by the end of the week, signaling that Republicans are ready and willing to invoke the nuclear option to confirm Gorsuch in the face of mounting Democratic opposition.

"I am proud to say that this good man, and this good judge, who has offered himself to serve our country on the United States Supreme Court, will be confirmed by the end of this week. And he should be," Cornyn said in a statement.

Earlier Monday, Sen. Lindsey Graham, R-S.C., once a strong opponent of changing Senate rules to allow for simple, 51-vote majorities for presidential nominations, has changed his tune in the face of a Democratic filibuster of Gorsuch.

"We're headed to a world where you don't need one person from the other side to pick a judge," Graham predicted Monday before the Judiciary Committee was expected to vote along party lines to support Gorsuch's confirmation.

The South Carolina Republican also said GOP leaders are being forced to change the rules, and will go ahead and do so because "we're not going to change the nominee."

"If we have to, we will change the rules, and it looks like we will have to," he said.

Graham's remarks early Monday came amid announcements by several holdout Democratic senators, including Sens. Dianne Feinstein of California, Patrick Leahy of Vermont, Mark Warner of Virginia and Chris Coons of Delaware, that they will vote to sustain a filibuster of Gorsuch and against final passage. With the addition of those senators, Democrats now have the 41 votes they need to block Gorsuch unless the GOP goes nuclear.

Republicans also appear to have the backing they need to "go nuclear" and set a new simple-majority voting precedent for Supreme Court nominees.

In addition to Graham, at least five more moderate Republicans have either come out squarely in favor of going nuclear to confirm Gorsuch or have signaled a willingness to be persuaded to vote to change the rules.

The so-called nuclear option would change Senate rules to require only a simple 51-vote majority to confirm Supreme Court justices and would circumvent the need to shut down a filibuster, which requires 60 votes.

The rules change would set a new precedent for the way the Senate confirms high court judges by preventing the minority's ability to block a nominee. In the process, it would further stoke partisan tensions in Congress. In turn, that likely would make it harder to pass a funding bill to keep the government up and running later this month.

But Republicans believe Democrats are leaving them no choice by trying to obstruct Gorsuch, who the American Bar Association has given its highest "well-qualified" rating.

Sen. John McCain, R-Ariz., who along with Graham served as a member of the "Gang of 14" that a decade ago negotiated a deal to avoid the nuclear option, last week also wouldn't commit to opposing any effort by McConnell to invoke the nuclear option on Gorsuch.

"I would address that issue when it arises," McCain said when asked if he would back a Senate rules change to seat Gorsuch.

Sen. Susan Collins, R-Maine, last week said Gorsuch is "eminently well-qualified" and doesn't deserve to be filibustered, as Senate Minority Leader Chuck Schumer, D-N.Y., has vowed to do.

"There are no grounds for a filibuster of Neil Gorsuch," she told reporters Tuesday afternoon.

Asked if she would support a decision by Senate GOP leaders to "go nuclear," Collins said: "I am not eager to see the rules changed, so I hope that Democrats do not launch a filibuster against an eminently well-qualified nominee."

"I'm hoping we're not going to get to that point — that's all I want to say," she added.

Last week, more centrist-oriented senators have seemed more open to the nuclear option to seat Gorsuch. Sens. Jeff Flake, R-Ariz., John Thune, R-S.D., and Rob Portman, R-Ohio, all have said they are not absolute "no's" on invoking the nuclear option.

Like McCain and Graham, Collins was part of what was known as the "Gang of 14," seven Republicans and seven Democrats, who agreed in 2005 not to allow Republican leaders to invoke the nuclear option in the case of lower court judges.

The seven Republicans, including Collins, were enough to deny the GOP leaders the 51 votes to approve the Senate rules change to make it easier to confirm lower-court judges.

Each senator in the "gang" agreed that they could only support a filibuster in "extraordinary circumstances" — with each free to define what that meant and trusting each other enough for the pact to stick.

But those days of comity and trust are over after former Senate Majority Leader Harry Reid, D-Nev., invoked the nuclear option for all presidential nominations except those to the high court in 2013.

Partisan tensions frayed further last year when Senate Majority Leader Mitch McConnell, R-Ky., prevented Judge Merrick Garland, President Barack Obama's choice to fill the Supreme Court vacancy, from receiving a hearing or a vote on the floor for nearly a year.