WASHINGTON — Senate Republicans are open to holding a lame duck Supreme Court confirmation if Justices Samuel Alito and Clarence Thomas change their mind about not retiring after the midterm blue tsunami.

“It can be done,” Senate Majority Leader John Thune (R-SD) told Punchbowl News. “You’re talking about basically 60 days post-election in the lame duck.”

“I certainly wouldn’t rule that out.”

Republicans find themselves in a situation eerily similar to Democrats in 2014, when liberal Justice Ruth Bader Ginsburg, 81, a progressive darling, stayed on the Supreme Court after Republicans swept the Senate by stronger margins than expected.

She died six years later, allowing President Trump to appoint her successor, paving the way for a big conservative majority on the high court, which allowed it to overturn Roe v. Wade in 2022.

Thomas, 78, and Alito, 76, are similarly revered among many conservatives. But both have told allies they will not step down early.

“[They] have both been very clear that they don’t intend to retire this term. I don’t expect that decision to change,” one Supreme Court insider told The Post.

Many key Republicans, such as retiring Sen. Thom Tillis (R-NC) and Senate Judiciary Committee Chairman Chuck Grassley (R-Iowa), have all signaled support for rushing through a nominee if needed.

There hasn’t been a Supreme Court retirement during a lame-duck session after a midterm election since 1922, when Mahlon Pitney stepped down, data from the Congressional Research Service show.

Given the size of the Democrats’ victories in Senate races, Republicans could be locked out of power in the upper chamber into at least the 2030s.

“I wish they would have retired in the spring,” one GOP Senate advisor told The Post. “[The] country will face the consequences of them not retiring in the spring for many years.”

But pressuring Alito or Thomas to change course would likely be futile, according to that source. Sen.-elect Sherrod Brown (D-Ohio) is set to be sworn in early next week, and there are uncertainties over how moderate Republican senators would handle a last-minute confirmation effort.

“I don’t think it would work or anyone thinks there’s a real chance,” the advisor said of a hypothetical pressure campaign against Alito and Thomas.

Thomas will become the longest-serving justice in May, 2028 if he stays on the high court.

Then there’s also the risk of pushing Democrats toward packing the Supreme Court if they take the White House in 2028.

One idea floated by Sarah Isgur, a Supreme Court luminary, is the possibility of Trump attempting to nominate candidates to succeed Thomas and Alito without a vacancy and to get the Senate to confirm them.

But many insiders were skeptical of that approach, fretting that it would ensure Democrats pack the high court in the future and raising process concerns.

Republican appointed justices have had at least five seats on the Supreme Court since the 1970s, with a few brief exceptions, including the stretch of time following late Justice Antonin Scalia’s death in 2016 at the age of 79.

Right now, Democrats are projected to get at least 54 Senate seats and are within striking distance of nabbing two more, depending on how the races in Alaska and Mississippi shake out.