Washington — President Trump endorsed Rep. Mike Collins in the upcoming Republican Senate runoff in Georgia on Sunday, wading into the race days ahead of the contest that will decide who takes on Democratic Sen. Jon Ossoff. 

"Mike Collins is a true Friend, Fighter, and WARRIOR, who has been with us from the very beginning, and has my Complete and Total Endorsement to be your next United States Senator," Mr. Trump said in a post on Truth Social early Sunday. 

Collins is facing off against former college football coach Derek Dooley in Tuesday's runoff, after no Republican candidate cleared 50% of the vote in last month's primary. Republicans have been vying to take on Ossoff in the Peach State, which is home to one of the most closely watched Senate races of the cycle — and could determine control of the upper chamber. 

With Ossoff the sole Democrat seeking reelection in a state the president won in 2024, Republicans have been eyeing a pickup opportunity in Georgia. But the inability to coalesce behind a GOP nominee has complicated the path forward.

After a third candidate, GOP Rep. Buddy Carter, was eliminated in last month's primary, Collins and Dooley have faced off for the nomination. Collins, the owner of a trucking business, has represented Georgia in the House since 2023 and finished first in the runoff with almost 41% of the vote. Dooley is an attorney who coached football at the University of Tennessee and is the son of legendary University of Georgia football coach Vince Dooley. He secured around 30% of the vote last month.

While Collins positioned himself as a staunch supporter of the president, Dooley hasn't embraced Mr. Trump as readily, billing himself as a political outsider while pledging to work with the president for Georgians.

Dooley said on Sunday that he has "great respect for President Trump" and looks forward to working with him. He wrote on X that "the most important endorsement is that of the Georgia people," while arguing that he's better situated to beat Ossoff. 

Mr. Trump's endorsement sets up a proxy battle with Gov. Brian Kemp, who threw his support, and his formidable state political operation, behind Dooley. The president and Kemp have been at odds since the 2020 election when Kemp resisted Trump's efforts to intervene in Georgia's presidential election results. 

In his post on Truth Social Sunday, Mr. Trump said "I don't know Derek Dooley, and neither does anyone else, but he seems like a nice person," before mentioning the 2020 election results in Georgia. 

The president lauded Collins as a "very successful Businessman" who he said is "always fighting tirelessly for our America First Agenda."