UPDATE: Early Tuesday, Sen. Mitt Romney released a statement indicating that he would not hold up a vote on President Donald Trump’s forthcoming Supreme Court nominee.

The list of Republicans who may oppose a swift vote on President Donald Trump’s forthcoming Supreme Court nominee dwindled quickly Monday.

It may be down to just one.

Sen. Mitt Romney, R-Utah, hasn’t said what he’ll do, but he may give us all an idea Tuesday afternoon.

Republicans have a 53-47 majority in the Senate, meaning they can afford just three defections and still be able to confirm a replacement for Justice Ruth Bader Ginsberg, who died Friday (with Vice President Mike Pence casting the tiebreaking vote).

So far, two Republican senators have broken ranks. Maine’s Susan Collins and Alaska’s Lisa Murkowski. Will Romney be the third?

His office says he plans to speak to the media sometime after Tuesday’s GOP conference lunch where he will hear Senate Majority Leader Mitch McConnell make his case.

Whatever he plans to do, Romney hasn’t yet tipped his hand.

Most of the other possible Republican renegades have fallen in line. Colorado’s Cory Gardner, who is in a tough re-election battle in November says he will support quickly moving to fill the Ginsberg seat, as will Tennessee’s Lamar Alexander and Iowa’s Chuck Grassley.

Romney is already under immense pressure from both the left and right as he weighs a course of action. Until he takes a public position, he’s a sort of political “Schroedinger’s Cat,” both Democratic ally and Republican stalwart. Both sides believe his vote during this process is “gettable.”

And for those who don’t want to see Trump name Ginsburg’s replacement, Romney is likely vital. Democrats need four Republicans to cross over to stop a nomination before Election Day and Romney would only be the third.

If Mark Kelly beats Republican Sen. Martha McSally in Arizona’s special election this November, he’ll be installed later that month. Kelly is ahead in recent polling. He could be a fourth vote to block a Trump nominee, but once again that hinges on some other Republican joining Collins and Murkowski.

The left sees Romney as swayable because of his willingness to criticize the president and his historic, and lonely, vote to remove Trump from office during the Senate impeachment trial. For those very same reasons, there are some on the right who are suspicious of him, but he still was the party’s presidential nominee in 2012, so some wonder how far will he really stray with a lifetime Supreme Court appointment on the line.

Spencer Stokes, who served as Sen. Mike Lee’s chief of staff, thinks Romney will stay true to his conservative principles and move forward with the nomination process.

“I don’t think either of our senators bow to pressure on anything,” Stokes said. “They have their own internal moral compass. They’ll make a decision based on that.”

Stokes believes Romney’s top consideration will be the long-term ideology of the Supreme Court rather than any desire to derail Trump. He doesn’t expect Romney to balk at the opportunity to increase the court’s conservative majority to 6-3.

This will be Romney’s first experience with a Supreme Court confirmation.

He was supportive of Trump’s previous two choices — Neil Gorsuch and Brett Kavanaugh. Although he was not in office, Romney said he would have voted to confirm Kavanaugh. He also called Trump’s selection of Gorsuch for the high court “superb.” In fact, Gorsuch was considered to be a frontrunner as a Supreme Court nominee had Romney won the presidency in 2012.

One consideration for Romney may be the timing of a confirmation. Should the Senate push through a nomination before the election or vote on it afterward? Delaying the vote on a nominee until after the election could provide some political cover for vulnerable Republican incumbents like Gardner and Collins, allowing them to avoid taking a tough vote before the November election. But, that strategy has a big risk attached to it. If Republicans lose their Senate majority or Trump loses the election, or if both happen, that could throw a wrench into those calculations.

Or Romney may keep the whole country guessing like he did during the impeachment trial, only revealing he would vote to remove the president shortly before the final tally. He may want to see Trump’s pick before outlining his plans.

Romney can afford to take a little longer to decide. There’s very little chance he will face any electoral consequences no matter what he decides. He’s not on the ballot again until 2024.

Political action committees are thinking about the 2020 election and already planning ad campaigns, including targeting Romney in Utah.

“Romney is comfortable enough in his own skin to make this decision based on what he thinks is right,” Stokes said. “Spending time and money putting pressure on him is a waste.”