President Donald Trump escaped two of the more uncomfortable Republican runoff tests of the 2026 cycle Tuesday night, just as prediction markets expected he would.
Sen. Darline Graham Nordone won South Carolina’s special GOP Senate nomination over Rep. Ralph Norman, while Mike Mazzei edged Attorney General Gentner Drummond for Oklahoma’s Republican gubernatorial nomination.
Both results validate the prediction markets’ second look. Graham Nordone was trading at around 84% after being forced into a runoff, while Mazzei was priced at near 78% after a June primary in which he had entered as a near-90% favorite but finished just behind Drummond.
Traders correctly read that a one-on-one runoff would favor the president’s picks.
Still, the results are less a clean declaration of Trump’s absolute control than a reminder of its boundaries. His candidates won, but neither race was as easy as the political fundamentals suggested it should be.
Graham delivers the South Carolina win
Graham Nordone defeated Norman by roughly five points, winning about 52.5% of the vote after entering the runoff with the full support of Trump, Sen. Tim Scott and the South Carolina Republican establishment. The result puts her on track to become South Carolina’s first elected female senator and keeps the late Sen. Lindsey Graham’s Senate seat in the family after his death earlier this summer.
It was also an important political save for Trump. Graham Nordone had finished first in the August 11 special primary, but only with about 33% of the vote, a weak showing for a sitting senator with the president’s endorsement in a crowded, overwhelmingly Republican field.
Her failure to clear the 50% threshold gave Norman a path to turn the runoff into an anti-succession race, criticizing her political inexperience and suggesting voters should choose someone other than the appointed sister of a longtime senator.
Trump responded by leaning in. He rallied for Graham Nordone in Myrtle Beach, helped consolidate key GOP figures behind her, and turned the final stretch into a referendum on whether South Carolina Republicans would stand with the president’s choice. It worked. But the fact that it required a runoff at all remains meaningful in a solidly red state.
Mazzei wins the closer test
Mazzei’s Oklahoma victory was even narrower. He beat Drummond 50.3% to 49.7%, a margin of roughly half a percentage point in a runoff that became one of the year’s clearest tests of whether Trump’s endorsement could overcome a well-known statewide official with a homegrown base.
The result reversed the order from June, when Drummond finished first in the crowded primary, 26.3% to 26.0%, despite Trump endorsing Mazzei before Election Day. Markets had priced Mazzei near 90% before that primary, which made his second-place finish one of the more notable prediction-market misses of the cycle.
But traders stayed with him for the runoff, and they were right. Mazzei’s 78% pricing on Kalshi and Polymarket reflected a belief that consolidation would work in Trump’s favor once the field narrowed to two candidates. The forecast held, even if the final margin made clear how little room Mazzei had for error.
Prediction Markets were right after stumble
The common thread in both contests is that the first round created doubt, while the runoff contracts correctly treated Trump’s endorsement as more valuable in a binary race.
In South Carolina, Graham Nordone’s 84% probability after the primary looked aggressive given the precedent set by Lt. Gov. Pamela Evette. Evette, a Trump-backed South Carolina gubernatorial candidate, had been forced into a runoff earlier this year and then lost to Alan Wilson. In Oklahoma, Mazzei’s 78% price had to overcome the fact that his near-90% first-round market price failed outright.
Yet the markets were right on both. Graham Nordone’s five-point victory was solid enough to justify the favorite pricing. Mazzei’s razor-thin win was less comfortable, but a win is still a win.
The episode is a useful reminder that markets can adjust to new information, especially when a fragmented primary becomes a simple two-candidate runoff.
Trump’s power remains real, not total
Tuesday’s results are wins for Trump, but they do not erase the broader 2026 pattern.
Trump’s endorsements have helped candidates such as Mazzei and Graham Nordone, and the president remains the central force in Republican primaries. But the year has also produced limits: Evette lost after Trump initially endorsed her, while other Trump-backed candidates have been pushed into runoffs or lost. Even in Oklahoma, Mazzei needed a second election to beat a candidate Trump had dismissed as a “fake Republican.”
That matters because both South Carolina and Oklahoma are solidly Republican states. If Trump’s choices can struggle there, it suggests that local candidate quality, turnout and state-level relationships still matter, even when the president is all-in.
A faint Democratic opening?
Norman’s concession speech added one more wrinkle. He warned that the hard-fought GOP runoff had given Democrats exactly what they wanted: a chance to argue that Graham Nordone is vulnerable in November after spending weeks under attack from fellow Republicans.
Democrats see at least a glimmer of opportunity against Graham Nordone. But in practical terms, South Carolina remains a very difficult Senate target. The state is not central to the path for Senate control, and Republican nominee Graham Nordone will begin the general election as a heavy favorite over Democrat Annie Andrews. The race is likely too far of a stretch to garner much action on prediction markets.
The more realistic takeaway is narrower. Tuesday did not turn South Carolina blue or prove that Trump is losing the GOP. It showed that he can still get his candidates over the line when he concentrates his political capital, but also that, even in the reddest states, his support is no longer enough to make the vote feel automatic.
