The Michigan governor race is settling into a pretty clear shape with prediction markets feeling very confident.
U.S. Rep. John James looks set to cruise through the GOP primary. Secretary of State Jocelyn Benson is all but locked in on the Democratic side. And prediction markets are treating Democrats as the likely winners in November despite President Donald Trump carrying the state in 2024.
Traders don’t appear to expect much suspense during the August 4 primaries or November general election. The volume on prediction markets appears to be more about how much Trump’s endorsement still matters on the Republican side and how little the market seems to fear a party switch in Lansing with Democratic Gov. Gretchen Whitmer set to leave office.
James has the Republican lane
James is running away with the GOP primary, at least according to prediction markets, and the numbers are lopsided enough to make August 4’s vote look more like a formality than a real contest.
He’s at 85% on Kalshi on $576,000 in volume and 86% on Polymarket on $85,000. Businessman Perry Johnson is stuck in the teens, and former U.S. Rep. Mike Cox dropped out last week after Trump backed James.
That’s a familiar pattern by now during the 2026 midterm election cycle. Once Trump makes his preference clear, the rest of the Republican field tends to collapse around it. Prediction markets then pile on that side.
James’s advantage also fits the broader Trump endorsement story this cycle. Trump-backed candidates gained real traction in Senate races in places like Louisiana and Texas, where his picks helped knock out or overtake incumbent Republicans who had challenged him in the past. Michigan is following that same script on the governor side, with Cox’s exit underscoring just how much party loyalty still runs through Trump’s blessing.
In the Arizona gubernatorial primary Tuesday, prediction markets also heavily favored U.S. Rep. Andy Biggs, a Trump endorsee, to nab the GOP nomination. Biggs won with 74% of the vote.
Benson is basically sealed up
The Democratic primary is far less interesting from a prediction markets standpoint. Kalshi prices Benson at 96.8% and Polymarket at 98%, which is basically the market saying there’s nothing left to debate.
She’ll look to carry the torch of two-term governor Whitmer. Benson has served as Whitmer’s Secretary of State since 2019.
The latest polling backs up the prediction markets too. Benson leads Genesee County Sheriff Chris Swanson by 60 points in the latest Democratic primary poll and has the name-ID edge that usually makes a nomination race over before it starts.
That also means Benson will enter the general election as the candidate Democrats have been banking on for months. She has the advantage of being the outgoing Secretary of State and the clearest heir to Whitmer’s Democratic coalition. If the primary is a lock, the general election becomes the real test of whether Michigan is still a swing state or just a state that likes to keep things close on paper.
Markets like Democrats in November
Despite a likely tight Senate race in November, prediction markets are heavily leaning toward Democrats in the general despite Trump winning the state in 2024. Kalshi has Democrats at 82% to win the governor’s race on $276,000 in volume, and Polymarket is basically identical at 82% on $192,000. Traders appear to believe Benson is a strong enough candidate to hold the mansion even in a state that is still politically split down the middle.
Polling reinforces her strength. General election numbers in June had Benson ahead by up to 11 points, though with a lot of undecided voters still in the mix. So the market is not saying the race is over, simply that Michigan probably isn’t ready to hand the governor’s office back to Republicans just because Trump won the state last cycle.
That makes Michigan another example of the 2026 midterm’s recurring pattern showcasing Trump can still decide Republican primaries, but that doesn’t always mean he can decide the general election.
