Donald Trump’s choice of Pete Hegseth to run the Defense Department is in jeopardy amid questions from some key GOP senators over whether he’s fit for the job, forcing the president-elect’s team to maneuver behind the scenes to avoid a second Cabinet pick from collapsing amid a Republican revolt.

No Republicans have said they will not support Hegseth, but even some of the GOP senators closest to Trump, including Sen. Lindsey Graham, are now wondering whether Hegseth can survive the tightrope walk to confirmation, sending an ominous signal for the incoming White House. Hegseth will need to limit defections to three GOP senators, assuming all Democrats vote against him, and there are already more than three senators who are uncertain if they’ll back him.

“He obviously has a chance to defend himself here. But some of this stuff is – it’s going to be difficult,” Graham, a longtime military veteran and South Carolina Republican, said on Tuesday. Hegseth, who has denied any wrongdoing, is under intense scrutiny amid a series of misconduct allegations, including a sexual assault allegation from 2017, which he has denied and in which no charges were filed.

Even as many GOP senators insisted to reporters this week that they haven’t asked Hegseth about the allegations in private conversations with him, other GOP senators and senior aides are growing frustrated by the drip-drip of negative coverage about him

The incoming chairman of the Senate Armed Services Committee, Roger Wicker, told CNN that he expects to see a whistleblower report outlining allegations of misconduct during Hegseth’s time running a veterans’ group. The New Yorker this week detailed the allegations in the report.

“I’m sure I’ll see it,” the Mississippi Republican told CNN. The New Yorker did not name the employees who compiled the whistleblower report and CNN has not independently reviewed the report. Other reports have also emerged about Hegseth’s conduct while employed at Fox News.

Trump’s team has carefully choreographed Hegseth’s first few days on the Hill in an attempt to create a sense of positive momentum, in what one Senate GOP aide described as “operation warp speed coalition-building.” But despite the efforts, expressions of doubt from Republican senators have continued to surface.

Hegseth, a former conservative commentator, has devoted recent days to meeting many of Trump’s closest allies, including some who appeared on Hegseth’s own program during his time at Fox News.

He’s even working to expand his outreach on the other side of the Capitol: He plans to meet with a group of House Republicans — the Republican Study Committee — on Tuesday, according to a person familiar with the discussions. In another sign of how seriously the transition team is taking GOP concerns, Hegseth is expected to sit for an interview with Fox News on Wednesday, two people familiar confirmed to CNN.

Supporters of the pick are hoping Hegseth’s answers will alleviate the concerns that several Republican senators have expressed. His anticipated interview is notable because most, if not all, of Trump’s Cabinet picks have been told to stay away from media appearances until after their confirmation process.

Key Republicans have emphasized that they want to see Hegseth be subject to an FBI background check, a typical part of nomination vetting, but a process as Trump has floated that he may not require nominees to undergo — and many say they worry about a high-profile confirmation hearing, which is traditionally one of the first of a president’s cabinet.

Some Hill Republicans say they are even privately watching for potential alternatives, including one of their own: Sen. Joni Ernst of Iowa, according to a person familiar with the conversations.

Two of Trump’s picks for his new administration have already pulled their names out of consideration, including the high-profile withdrawal of former Rep. Matt Gaetz of Florida, Trump’s pick for attorney general, who faced his own sexual misconduct allegations – which he also denied. Trump’s pick to lead the Drug Enforcement Administration withdrew on Tuesday.

Commenting on the Hegseth selection, Graham said, “leadership comes from the top. And I want to make sure that every young woman who joins the military feels welcomed and respected.”

Graham isn’t the only GOP senator to acknowledge the growing pileup of allegations against Hegseth.

Sen. Cynthia Lummis of Wyoming, another key Trump ally, said, “Some new things that have come to light in the last 12 to 14 hours are things he needs to address.” Sen. Kevin Cramer of North Dakota said “of course” the allegations are “concerning.” Sen. James Lankford of Oklahoma said he believed it was “reasonable” and “fair” to ask about allegations that Hegseth was intoxicated at work events.

“The president … should have the ability to make decisions on who they want as their advisers. But the Senate has a constitutional role as well,” Lankford said.

Sen. Bill Cassidy said the allegations “have to be addressed,” and emphasized the importance of a thorough vetting process for Trump’s Cabinet picks.

The Louisiana Republican added, “many people go through a rough period in their life.”

Meanwhile, Hegseth hasn’t announced meetings with any Democratic senators — a move that’s atypical in the Senate’s nomination process.

It’s an unorthodox strategy, but one that Trump and his allies believe will help them successfully fill the top Pentagon post. The focus on Republican votes — starting with Trump-friendly names and working outward — is designed to help insulate Hegseth.

“If he meets with us, he’ll be asked some of the obvious tough questions so maybe he wants to avoid them,” Sen. Richard Blumenthal, a Connecticut Democrat who sits on the Armed Services Committee, told CNN.

“Unlike Supreme Court justice nominees, there has been no indication that he’s coming to us in a bipartisan spirit, seeking our support. He isn’t asking for our support. That’s also a mystifying and astonishing fact. No one. Absolutely no one has reached out and said ‘Why don’t you sit down with this guy and really get to know him and see what his explanation is.”

Many in the Senate GOP said their main line of questioning for Hegseth will be more about his plans to reform the Pentagon, while giving him the “benefit of the doubt” about allegations against him, as Sen. Mike Rounds of South Dakota put it.

“He’s denied any wrongdoing. My main interest is, what kind of cultural shift are we going to see in the Pentagon?” Sen. Eric Schmitt of Missouri said, adding that no charges were ever filed against Hegseth.

“President Trump .. has got a right to pick who he wants to lead the Department of Defense and I think that Pete Hegseth right now is in a pretty strong position,” he added.

With the Senate’s narrow margins next year, the focus will be on GOP more moderate and establishment voices like Maine Sen. Susan Collins, Sens. Lisa Murkowski of Alaska and Mitch McConnell of Kentucky as well as incoming Sen. John Curtis of Utah.

Collins told CNN she believes Hegseth needs to go through the full congressional vetting process, including an FBI background check, before he is confirmed.

“As I’ve repeatedly said to you, I believe that we need an FBI background check to evaluate the allegations,” she told CNN on Tuesday, adding that Hegseth should complete the usual questionnaire about his background and participate in a public hearing. Collins has not yet met with Hegseth.

Republicans are also closely watching Ernst, who — as the first female combat veteran elected to the Senate — has raised concerns about Hegseth’s prior comments that women should not serve in combat roles.

“I’m straight up just saying that we should not have women in combat roles,” Hegseth said on a podcast in early November.

Ernst has previously said that she wants to have “a hard discussion” with him about the role of women in combat roles.

Hegseth told reporters on Tuesday whether he believed women should be in combat. His response: “I think they’re already in combat.”

CNN’s Kaitlan Collins, Danya Gainor, Morgan Rimmer, Ali Main, Ted Barrett and Haley Talbot contributed.