President Donald Trump on Friday tweeted his endorsement of Bill Hagerty, the U.S. ambassador to Japan, for the open Senate seat in Tennessee, likely limiting what could have been a crowded GOP field for the seat.  

Republican Sen. Lamar Alexander is not running for fourth term.

Trump carried the Volunteer State by 26 points in 2016, and he remains popular enough among GOP voters that a contested primary would likely have hinged on who appeared to be most loyal to the president. In the minds of primary voters, Trump may have just answered that question with this early endorsement. 

Hagerty has not yet announced his campaign. But he’s been expected to run, especially after former Gov. Bill Haslam announced Thursday that he would not to seek the seat. A former private equity executive, Hagerty had served in Haslam’s cabinet.

“Tennessee loving Bill Hagerty, who was my Tennessee Victoy [sic] Chair and is now the very outstanding Ambassador to Japan, will be running for the U.S. Senate,” Trump tweeted. “He is strong on crime, borders & our 2nd A. Loves our Military & our Vets. Has my Complete & Total Endorsement!”

In the wake of Haslam’s announcement, several other prominent Tennessee Republicans passed on the race. Rep. Mark Green said on Thursday he wouldn’t run. The freshman Republican had talked about challenging Alexander in a primary before the senator announced his retirement. But without Haslam in the race as his foil, Green, who was a former Trump nominee for Army secretary, wouldn’t have had as clear a pro-Trump lane. 

Former Rep. Diane Black, who lost a bid for the GOP gubernatorial nomination last cycle, also declined to run. 

Nashville orthopedic trauma surgeon Manny Sethi s already in the race. He is close to former Senate Majority Leader Bill Frist, with whom he edited a book about health policy. Sethi reportedly loaned his campaign $1 million and has raised $550,000 since he entered the race last month. He’s recently also picked up the backing of former state party Chairwoman Susan Williams. 

With Haslam out, two-term Rep. David Kustoff was considering entering the Senate race on Thursday. Trump endorsed Kustoff less than a week before his August 2018 primary, when he was being outspent more than 2-to-1 by a perennial candidate and self-funder. Kustoff, one of two Jewish Republicans in the House, easily survived. But now that he can’t claim the president’s support in a Senate primary, he might be reconsidering getting into the race. 

Kustoff’s predecessor in the 8th District, former Rep. Stephen Fincher, was also thought to be eyeing the Senate race. He briefly ran for the GOP nomination for the state’s other Senate seat last year, arguing that he would help the president enact his agenda. But Fincher would have had a harder time styling himself as a Trump ally. He was an outspoken defender of the Export-Import Bank, which pitted him against more conservative members of his party. As a member of the House Financial Services Committee, he led the effort to reauthorize the agency through a discharge petition in the fall of 2015. 

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