By Manu Raju, Clare Foran and Ted Barrett, CNN

(CNN) -- Senate Majority Leader Mitch McConnell is moving closer to locking down enough support to pave the way for confirmation of a new Supreme Court nominee in the midst of a hugely consequential election year,ratcheting up calls for a quick vote that could fundamentally alter the court in a sharply more conservative direction for decades to come.

Two key GOP senators -- Cory Gardner, who is facing a tough reelection fight in Colorado, and Chuck Grassley of Iowa, who had previously suggested he was opposed to filling a vacancy this year -- signaled on Monday that they would be open to confirming a nominee, a sign that McConnell is at this stage closer to having the GOP votes he would need to secure confirmation of a new justice.

While Senate Republicans are still uncertain about the timing of the vote, party leaders are growing confident that they will confirm a nominee -- either right before the election or soon after, no matter the outcome and despite taking the opposite position four years ago when then-President Barack Obama sought to fill a vacancy during an election year.

Asked on Monday if the Senate would confirm a Trump nominee in a lame-duck session if Biden wins, GOP Sen. John Cornyn of Texas said: "You mean while we're still in our term office, and President Trump is? Of course."

And Senate Judiciary Chairman Lindsey Graham, a South Carolina Republican, said on Fox News that Republicans will confirm Ginsburg's replacement before Election Day.

"The nominee going to be supported by every Republican in the Judiciary Committee and we have the votes to confirm the judge, the justice, on the floor of the Senate before the election, and that's what's coming," Graham said.

Graham's comments are all the more remarkable because there is no nominee and he's asserting that Republicans are already vowing to give Trump's pick final approval in what would be one of the quickest Supreme Court confirmations in modern history.

Currently, there are 53 GOP senators -- meaning they can only lose three Republicans if Vice President Mike Pence stepped in to cast a tie-breaking vote.

So far, two Republicans -- Lisa Murkowski of Alaska and Susan Collins, who is facing a competitive reelection fight in Maine -- have voiced opposition to taking up whomever Trump nominates to fill the late Justice Ruth Bader Ginsburg's vacant seat before November 3. But it is unclear if there will be any further Republican defections.

GOP Sen. Mitt Romney of Utah has not yet said where he stands, saying on Monday, "I'm not going to speak about this until I had a chance to speak with my colleagues." But even if he were to come out against moving forward with a nominee, it is not clear whether there would be a fourth Republican senator who would follow suit, and many Republicans believe it is doubtful a fourth would break ranks.

Of course, the President has yet to formally name a nominee and his decision of who to pick will have a bearing on how senators ultimately decide to vote. It is also impossible to predict how the confirmation process will unfold in the Senate and what hiccups could be yet to emerge for any nominee.

But statements from Gardner and Grassley on Monday could serve to fuel momentum for the Senate GOP conference to unite behind moving quickly to advance a nominee.

On Monday evening, Gardner signaled that he is not opposed to confirming a nominee close to an election, saying in a statement, "I have and will continue to support judicial nominees who will protect our Constitution, not legislate from the bench, and uphold the law. Should a qualified nominee who meets this criteria be put forward, I will vote to confirm."

In 2016, after Obama announced the nomination of Merrick Garland to the Supreme Court following the death of Justice Antonin Scalia, Gardner said in a statement, "The next president of the United States should have the opportunity to fill the vacancy on the Supreme Court."

"Our next election is too soon and the stakes are too high; the American people deserve a role in this process as the next Supreme Court Justice will influence the direction of this country for years to come," he said at the time.

Grassley, the Senate Finance Committee chairman and a former chair of the Senate Judiciary Committee, signaled on Monday that he is on McConnell's side, despite suggesting in July that he wouldn't favor moving ahead with a nomination this year if he were still chairman of the committee.

In a statement Monday, Grassley said, "Once the hearings are underway, it's my responsibility to evaluate the nominee on the merits, just as I always have," adding, "Make no mistake: if the shoe were on the other foot, Senate Democrats wouldn't hesitate to use their Constitutional authority and anything else at their disposal to fill this seat."

The looming Supreme Court fight puts vulnerable Republicans in a tough spot as Democrats call for any nominee to be put on hold for consideration until after the inauguration, and the high-stakes fight could have dramatic implications in the race for control of the Senate and the White House.

A statement from GOP Sen. Joni Ernst, who is facing a competitive reelection in Iowa and is on the Senate Judiciary Committee, did not address her view on timing.

In the statement, Ernst said, "We have much to consider over the coming days. The Supreme Court plays a fundamental role in the defense of our Constitution and in the protection of our rights and liberties. Once the president puts forward his nominee for the Supreme Court, I will carry out my duty—as a member of the Senate Judiciary Committee—to evaluate the nominee for our nation's highest court."

In a floor speech on Monday, McConnell defended his vow that a nominee will get a Senate vote, adding that "the Senate has more than sufficient time to process a nomination. History and precedent make that perfectly clear."

McConnell hasn't yet specified if a vote will happen before or after the election.

Sen. John Thune, the No. 2 Senate Republican, said on Monday that he doesn't know whether there are four Republicans who are against moving forward with a Supreme Court nomination vote before the presidential election. "It's hard," Thune said. "We haven't heard from everybody. We kind of know for the most part of where most of our members are, but until we get an opportunity with everybody together, I think it's probably a little early to speculate about that."

Some Republicans on Monday acknowledged that it may be challenging to confirm a new justice prior to Election Day, but suggested that confirmation could still proceed during a lame-duck session following the election even if former Vice President Joe Biden, the Democratic presidential nominee, were to win the White House.

Asked if it could be done in 43 days -- the amount of time left before the November 3 election, Cornyn said, "The ones that have been done more quickly have typically been done with a lot more cooperation. I think I'm not expecting much cooperation from the Democrats so they can probably string it out longer."

GOP Sen. Roy Blunt of Missouri, when asked if confirmation could get done before the election, said, "It would be the new recent world record .... we'd have to do more than we've done in a long time to get one done that quickly, but it's possible."

Asked if it would be fair to fair to vote in a lame duck if Trump loses, he said, "Well, a lot of presidents have lost and had judges confirm during the lame duck."

Thune declined to discuss a hypothetical on whether he would support a nomination vote during a lame-duck session if Trump lost the election.

"That's a hypothetical, I'm not gonna go into that," he replied.

While Trump has yet to name a nominee, he said on Monday that he plans to do so by the end of the week, saying it will likely happen either on Friday or Saturday.

Judge Amy Coney Barrett, a federal appellate judge and Notre Dame law professor, is currently viewed as a leading contender.

Republican Sen. Josh Hawley, who has said his support for a Supreme Court justice is contingent on whether the nominee believes Roe v. Wade, the landmark Supreme Court case on abortion, is "wrongly decided," said Barrett, an appeals court judge, meets that test.

Asked about Barrett, he said that "as to the question on Roe, Yes. I think she meets that standard."

This story has been updated with comments from Senate Judiciary Chairman Lindsey Graham.