Senate Republican Whip John Thune (S.D.) is urging President-elect Trump not to put his thumb on the scale in the race to elect a successor to outgoing Senate Republican Leader Mitch McConnell (Ky.), putting a new wrinkle in the high-stakes contest.

Thune in recent days has declared his preference that Trump give Republican senators space to make their own decision about who should lead the new Senate GOP majority, arguing it would be in Trump’s “best interests” to stay neutral.

That argument has been echoed by Thune’s allies, such as Sen. Markwayne Mullin (R-Okla.), who told CNN earlier this week that Trump should “stay out of the race.”

Thune’s comments are creating a stir among Senate insiders two days after Trump won a resounding victory over Vice President Harris and helped Republicans regain the Senate majority.

Allies of Thune’s two rivals in the leadership race, Sens. John Cornyn (R-Texas) and Rick Scott (R-Fla.), say that calls for Trump to stay out of the leadership race indicate that Thune is nervous that the president-elect would endorse either Cornyn or Scott — which would be a serious setback.

“He’s terrified. He knows that Trump won’t endorse him. If he knows that, then Trump getting involved hurts him,” a Senate Republican aide said.

Thune’s rivals have a better relationship with Trump, especially Scott, who’s the closest to the president-elect of the three.

Scott represents Trump’s adopted home state of Florida, and as National Republican Senatorial Committee chairman traveled to Mar-a-Lago in April of 2021, when Trump was still something of a pariah among GOP senators, to give him a “Champion of Freedom” award.

Scott was later challenged about it in an interview with ABC’s George Stephanopoulos, who asked if he was endorsing Trump’s “lies” about the 2020 election.

Trump on Thursday named Susie Wiles, who ran Scott’s first campaign for governor in 2010, as his White House chief of staff. She served as his presidential campaign manager. 

He was also the first senator to travel to New York to attend Trump’s criminal trial on charges of falsifying business records.

Scott and his allies are hoping that Trump will weigh in strongly on his behalf in the leadership race. Without Trump’s enthusiastic endorsement, he probably does not have a viable path to becoming majority leader, Senate Republican sources say.

Sen. Ron Johnson (R-Wis.), who has endorsed Scott, called on Trump Thursday to intervene in the leadership race.

“Jesse, if you’ve got any influence with President Trump, ask President Trump to come out publicly and say he wants to work with someone as accomplished as Rick Scott to accomplish his agenda,” Johnson asked conservative podcast host Jesse Kelly in an interview.  

Cornyn, who served as Senate GOP whip during Trump’s first two years in the White House, doesn’t have as good a relationship with Trump as Scott but his supporters argue he’s closer to the president-elect than Thune.

Cornyn spent time with Trump in recent weeks at a rally in Reno, Nevada, and a meeting in Austin, Texas.

He was also a special guest at fundraisers for the Trump-Vance campaign in Laredo, San Antonio and Houston in August. The Texas fundraising swing raised “well into the seven figures” for the Trump campaign, according to a source familiar with Cornyn’s political operation.

Cornyn has reminded Trump of their accomplishments working together when he served as the No. 2-ranking Republican in 2017 and 2018, including passage of the Tax Cuts and Jobs Act and confirming conservatives Neil Gorsuch and Brett Kavanaugh to the Supreme Court.

“As I told President Trump, I’m interested in getting the band back together again,” Cornyn told Fox News’ Neil Cavuto.

Thune has had rockier relationship with Trump in the past.

It hit a low point after Thune opposed an effort to object to the certification of electoral votes for Joe Biden after the 2020 election.

Trump got so made about Thune’s pledge to defeat objections to Arizona’s and Pennsylvania’s electoral slates four years ago that he called for the amiable South Dakota Republican to face a primary challenger in 2022.

“South Dakota doesn’t like weakness,” Trump tweeted in December of 2020. “He will be primaried in 2022, political career over!!!”

Thune, nevertheless, cruised to an easy reelection.

Thune has since tried to mend fences with Trump. He visited the president-elect at his Mar-a-Lago home in March and spoke to him on the phone Wednesday.

The No. 2-ranking Senate GOP leader has pledged to work closely with Trump to pass his legislative agenda in 2025 and 2026 if he is elected to become the next Senate majority leader.

But he advised Trump on Wednesday to let Senate Republicans make their own decision about who should lead the conference next year, defending what Republican senators have long viewed as their prerogative to run their own conference.

“I’m staying in regular contact with him and with his team and, obviously, if he wants to, he could exert a considerable amount of influence on that but, honestly, I think my preference would be and I think it’s probably in his best interest to stay out of [the race,]” Thune told CNBC’s Joe Kernen.

“These Senate secret-ballot elections are probably best left to the senators and he’s got to work with all of us when it’s all said and done,” he said.

Thune made similar comments in a Fox News interview, acknowledging that Trump could  swing the race one way or another.

“The president obviously has tremendous influence if he chooses to use it. I think in leadership elections, particularly in the Senate … it is a very sort of inside baseball thing,” he said, arguing that Senate Republicans will be able to find the right person for the job without outside influence.

“I think if he lets it play out, we’ll get the right person. I’ve had conversations with him and have told him that we want to get his team in place so that he can hit the ground running and get to work on an agenda to make sure that he and our team succeeds,” he said.

The last time a president played a major role in picking a Senate majority leader was in late 2002.

Sen. Bill Frist’s (R-Tenn.) close relationship with then-President President George W. Bush was a big reason why he was elected to succeed Senate Majority Leader Trent Lott (R-Miss.), who resigned from the leadership after making controversial remarks at late-Sen. Strom Thurmond’s (R-S.C.) 100th birthday party.

Frist had previously served as NRSC chairman but he didn’t work his way up the leadership ranks as other GOP leaders have done, and his management style as well as his deference to the Bush administration rankled some GOP senators.