Representative Mike Collins appears well-positioned to defeat former football coach Derek Dooley in Georgia's Republican Senate runoff after securing President Donald Trump's endorsement, with prediction markets giving him a commanding lead over his rival.

The primary runoff is being closely watched as the winner would become the Republican nominee and face Democratic Senator Jon Ossoff in one of the GOP's top pickup opportunities in the 2026 midterm elections.

As of Monday morning, prediction market platform Polymarket placed the odds of Collins winning the Republican Senate runoff at 98 percent, against Dooley's 2 percent. Similarly, Kalshi had Collins' odds at 98 percent and Dooley's at 2.4 percent.

On Sunday, Collins received an 11th-hour endorsement from Trump, with the president praising the trucking company owner and second-term congressman's loyalty and calling him a "warrior and a winner."

Dooley, a political newcomer, has been endorsed by outgoing Republican Governor Brian Kemp, who previously clashed with Trump over his refusal to overturn Georgia's 2020 election results.

The Republican primary was held on May 19, but neither Collins nor Dooley secured the majority needed to win the nomination outright. Collins finished first in the initial vote with 40.5 percent, while Dooley placed second with 30.2 percent, sending the race to a runoff.

Odds on Mike Collins and Derek Dooley

Collins has enjoyed a significant market lead over Dooley since last December—except in mid-May, ahead of the primary, when Dooley's odds (51.5 percent) overtook Collins' (47.5 percent), according to Polymarket.

By May 20, the day after the primary, Dooley's Polymarket odds had dropped to 5.1 percent, and Collins' had shot up to 95 percent.

Kalshi paints a similar picture, with Collins in the lead until May 14, when Dooley's odds stood at 51.1 percent and the congressman's at 47.8 percent. While the reversal was less dramatic than on Polymarket, Dooley's chances still fell sharply, dropping to about 14.7 percent within a few days.

Trump Endorses Collins

Trump threw his support behind Collins with a lengthy Truth Social post on Sunday, describing the Georgia congressman as a "true Friend, Fighter, and WARRIOR" who had backed his agenda "from the very beginning."

The president praised Collins' record in Congress and said he would help advance key Republican priorities, including tax cuts, border security and energy production.

"A very successful Businessman prior to becoming a distinguished U.S. Congressman, Mike has brilliantly served his Community, during a career loaded with accolades and wins, always fighting tirelessly for our America First Agenda," Trump wrote. "As your next Senator, Mike will continue to work hard to Grow the Economy, Cut Taxes and Regulations, Promote MADE IN THE U.S.A., Champion American Energy DOMINANCE, Strengthen our incredible Military/Veterans, Advance Election Integrity, Keep our Border SECURE, Stop Migrant Crime, Murderers, and other Criminals from illegally entering our Country, Ensure LAW AND ORDER, and Protect our always under siege Second Amendment."

The president criticized Ossoff, calling him a "Radical Left Dumocrat" and a "weak and pathetic Senator." He also called out Dooley for pushing back against claims that he won Georgia in the 2020 election.

"I don't know Derek Dooley, and neither does anyone else, but he seems like a nice person," Trump wrote. "Unfortunately, he has lived outside of Georgia for most of his life, didn't vote in 2020 or 2016, and said that I lost Georgia in 2020 when, in actuality, the facts have now proven that I won by a lot!"

Collins has repeatedly echoed Trump's claims about the 2020 election, calling it "legitimately rigged."

He celebrated the endorsement at a campaign stop on Sunday in the northern Atlanta exurbs, the Associated Press reported, saying, "I've always said that President Trump has this just impeccable ability to put his thumb on the scale at the right time."

Collins Continues To Lead in Polls

Recent polling conducted after the May 19 primary has also pointed to an advantage for Collins, though the latest survey suggests the race may have tightened.

A JMC Analytics and Polling survey conducted between May 26 and 27 among 600 likely Republican voters found Collins leading Dooley by 16 percentage points, 55 percent to 39 percent. The poll had a margin of error of plus or minus 4 percentage points.

Another survey, conducted by Quantus Insights on May 20 among 782 likely Republican voters, showed Collins with 53.5 percent support to Dooley's 37.2 percent, while 9.3 percent of respondents remained undecided. The poll had a margin of error of plus or minus 3.9 percentage points.

However, a more recent survey from conservative pollster InsiderAdvantage, conducted from June 13 to 14, showed a much narrower contest, with Collins at 48 percent and Dooley at 46 percent. The survey interviewed 800 likely voters and had a margin of error of plus or minus 3.31 percentage points.