Sen. Marsha Blackburn has won the Republican nomination for governor of Tennessee, NBC News projects, defeating Rep. John Rose in a race in which President Donald Trump declined to endorse.

Blackburn, 74, became the first woman to represent Tennessee in the Senate after she won her current seat in 2018; she had served in the House since 2003. If she wins the governor’s race, she would be the first female governor.

She will be a heavy favorite in the general election in the red state to succeed term-limited Republican Gov. Bill Lee. Jerri Green, a member of the Memphis City Council, won the Democratic nomination.

Blackburn is considered one of the most conservative members of the Senate, known for her stances on abortion and transgender rights and her criticism of China’s influence.

While Trump stayed out of the race, Blackburn and Rose both leaned on his name.

The Tennessee Freedom Fund, a pro-Blackburn outside group, has spent heavily to tie her to Trump, airing advertisements featuring clips of Trump referring to her as “an incredible person” and saying: “Fantastic job you did. We’re proud of you.”

At a rally in Washington in January, Trump praised Blackburn, saying, “Unfortunately, she’s running for governor,” and adding: “I’d love her not to. I begged her: ‘I said, ‘Marsha, don’t. We don’t want to lose you in the Senate.’”

But the Nashville Banner reported that Trump told members of Tennessee’s congressional delegation on a flight to Memphis on Air Force One that he would not endorse Blackburn because of his relationship with Rose, according to two members of Congress who were present for the conversation. Rose, who represents Tennessee’s 6th District, is a former state agriculture commissioner who also positioned himself as a loyal Trump ally.

It makes the race a rare Republican contest in which Trump has stayed on the sidelines. Trump has even double-endorsed GOP candidates in past races, like in South Carolina, where he added an endorsement of state Attorney General Alan Wilson to his backing of Lt. Gov. Pamela Evette ahead of a runoff Wilson won.

Rose spent almost $13 million self-funding his gubernatorial bid.

Blackburn is part of an unusually large group of senators running for governor in this election cycle.

GOP Sen. Tommy Tuberville won his party’s gubernatorial nomination in Alabama this year, while Democratic Sen. Michael Bennet lost his primary in Colorado. Democratic Sen. Amy Klobuchar will be on the ballot for governor in Minnesota next week.