WASHINGTON — Republican senators are preparing for a thorough vetting of Matt Gaetz, President Donald Trump’s pick to lead the Justice Department, with keen interest in details from a House Ethics Committee investigation into the former Florida congressman.

The ethics panel has been investigating Gaetz on and off since 2021, most recently focusing on alleged sexual misconduct, illegal drug use, accepting inappropriate gifts, obstruction and other allegations. But the results of that investigation may not become public because Gaetz resigned from the House of Representatives at noon on Thursday. The ethics committee only has jurisdiction over sitting members of the House of Representatives.

Trump’s choice of Gaetz was a surprise to almost everyone, including members of his own party and Justice Department officials — in part because of the ethics investigation, his past legal troubles and his reputation as a troublemaker in Congress.

A source familiar with the process told NBC News that Gaetz had consulted Trump on who would best lead the Justice Department. Gaetz did not ask for the role, that person said, but Trump asked him to take the job Wednesday morning, just hours before the decision was made public.

Many Republican senators, including members of the Republican Party-led Judiciary Committee that will oversee Gaetz’s nomination as attorney general, said they want to see the details of the House Ethics investigation into Gaetz.

“I think it would be helpful,” said Sen. Joni Ernst, R-Iowa.

Newly-elected Sen. John Curtis, R-Utah, said he would “absolutely” like to see the findings of the House Ethics Committee investigation, saying, “I don’t know the technical details, and whether or not we would see that, but I think that would be very relevant.”

The House Ethics Committee will meet Friday, three sources familiar with the meeting told NBC News. One of those sources said the release of the Gaetz report is expected to be among the items on the agenda. Punchbowl News previously reported Wednesday that the Ethics Panel planned to release a “very damaging” report on Gaetz on Friday, citing multiple sources familiar with the investigation.

But Gaetz’s resignation complicates matters, and the House committee has not yet indicated what it will do. Although the panel lost jurisdiction over Gaetz when he resigned, there is precedent for releasing ethics reports after or on the same day a lawmaker leaves Congress. It happened in the case of former Rep. Bill Boner, D-Tenn., two months after he resigned to become mayor of Nashville in 1987, and with former Rep. Buz Lukens, R-Ohio, on the day he resigned in 1990.

Senator John Cornyn of Texas, who serves on the Judiciary panel, said he would be open to issuing a subpoena to the House of Representatives panel to collect the evidence it has gathered.

“We need a full vetting of the nominees, not only to know if the nominee is qualified, but also to protect the president,” said Cornyn, a former member of the Republican leadership.

“I’m sure it’s not in his best interest,” Cornyn said, referring to Trump, “for there to be any surprises in the House Ethics Committee report.”

Sen. Lindsey Graham, R-S.C., the top Republican on the Judiciary Committee, said he didn’t think the Senate had the authority to subpoena House documents, adding: “I’d go to a monkey wrench … if they did that would try to sue for something here.’

Graham also said Trump did not consult him when choosing Gaetz. “Elections have consequences. He chose Matt Gaetz. Matt will appear before the committee and he will be asked tough questions, and we will see how he does,” Graham said.

Sen. Chuck Grassley, R-Iowa, who is likely to take over as Judiciary chairman in January, dodged questions Thursday about whether he wants to see the House ethics report.

“Well, we have a professional staff in the judiciary that will be fully engaged in the vetting, and all of those questions will be answered in the vetting process report,” Grassley said.

When Grassley was asked again if he would like to see it, he said, “I think we have a vetting process. Let it play out.”

Cornyn and other Republican senators said they believe they will get all of the important evidence from the ethics investigation, even if the report itself never comes to light, thanks to an FBI background check and other research conducted as part of Gaetz’s confirmation process in the Senate.

“I am confident that whatever the information and findings of the House Ethics Committee will ultimately be brought to light, either through the FBI background investigation or through the committee’s investigation of the nominee, or through questioning during the hearing,” said Sen. Susan Collins, R.-Maine.

Collins does not serve on the Judiciary Committee, but is a moderate Republican whose vote in the full Senate could make or break Gaetz’s nomination.

Under the usual process, once Gaetz is formally nominated, he will be questioned in at least one public hearing by members of both parties on the Senate Judiciary Committee. The panel will then vote on sending his nomination to the Senate, where a simple majority is needed to confirm him as attorney general.

If Republicans ultimately win Pennsylvania’s Senate seat, which is headed to a recount, Gaetz could lose four votes in the Senate and still win confirmation. Trump has also said he wants the ability to appoint his Cabinet members without a confirmation vote while the Senate is in recess.

While many Republican senators expressed bafflement Wednesday at Trump’s choice of Gaetz, given his lack of experience, the Ethics Commission investigation, his successful coup against then-House Speaker Kevin McCarthy, R-Calif., and a Justice Department sex trafficking investigation into the congressman that ended without charges last year, no one has dismissed him outright.

Sen. Lisa Murkowski, R-Alaska, another moderate, appeared to go the furthest, saying Gaetz’s nomination is not a “serious nomination for attorney general” and that it would be “a significant challenge” for him to be confirmed . And Ernst said of Gaetz on Wednesday: “He has his work cut out for him.”

In the 18 hours since he was announced as Trump’s pick to lead the Justice Department, Gaetz has already started making phone calls and calling some Republican senators to find out his chances of being confirmed next year, four sources with direct sources. knowledge of the outreach told NBC News.

In addition, Vice President-elect JD Vance and his team have made their own calls to Senate Republicans about Gaetz, two additional sources familiar with the calls told NBC News.

Gaetz will have to answer his questions during Senate hearings about past scandals and his qualifications for the role, senators said.

“I’m afraid he won’t be able to cross the finish line,” said Sen. Kevin Cramer, R-N.D. “and we’re going to spend a lot of political capital – I say, a lot of people are going to spend a lot of political capital – on something that, even if they pulled it off, you’d have to wonder if it was worth it.”

Cramer said he was concerned about Gaetz, especially the way he disrupted and truly destroyed the House of Representatives for months in his successful effort to oust McCarthy. you know, they’re ruining the reputation of the House of Representatives to the point where they didn’t, they didn’t ride the wave in this most recent (election).”

When asked directly whether he would vote to confirm Gaetz, Cramer said the Florida congressman would have to pass the Judiciary Committee first. “I never say what I will never do because I want to hear the case. … I would be open to it,” Cramer said. “But he has a very steep hill to climb to get many votes, including mine.”

Asked if there are any Republicans in the Senate who could thwart Trump and vote against his Cabinet nominees in general, outgoing Sen. Mike Braun, R-Ind., said: “A few of them, and I’m not going to say which ones. You still have to go through that process. And if there are things on your record that don’t make sense, you’re probably not going to survive the trial.”