Oklahoma 2026 Primary Preview: Open Races for Governor and Senate Headline the June 16 Ballot

• Oklahoma votes Tuesday, June 16, with open seats at the top of the ticket. Gov. Kevin Stitt is term-limited, and the U.S. Senate seat opened when Markwayne Mullin resigned in March to become homeland security secretary. A candidate needs more than 50% to win a primary outright, or the top two advance to an Aug. 25 runoff.
• Nine Republicans are running for governor. Attorney General Gentner Drummond led much of the cycle, topping 40% in earlier polls, but a late
• May survey showed a four-way dead heat: Mike Mazzei 22%, Drummond 22%, Chip Keating 21% and Charles McCall 18%. A runoff looks all but certain.
• Rep. Kevin Hern gave up his Tulsa-area House seat to run for Senate, and Trump's early endorsement makes him the front-runner in a five-way Republican primary. The question is whether he clears 50% on June 16 or is pushed to an August runoff.
• Hern's exit left the 1st District open, drawing an 11-way Republican primary that Trump entered by endorsing Tulsa pastor Jackson Lahmeyer. The other four incumbents are safe: Josh Brecheen, Frank Lucas, Tom Cole and Stephanie Bice, with Cole winning his last race at 65% and Bice at 60%.
• Prediction markets see no November suspense. Polymarket prices a Republican win for governor at about 92% and rates the open Senate seat a near-lock, and Kalshi places Oklahoma in its safe-Republican tier at 90%-plus. The real betting action is the June 16 primaries and the likely Aug. 25 runoffs.

OKLAHOMA CITY. Oklahoma holds its primary Tuesday, June 16, and the ballot is stacked with open seats. The Oklahoma 2026 primary will help pick a new governor, fill an open U.S. Senate seat, and sort out all five U.S. House races.

One rule shapes the whole night. In Oklahoma, a candidate needs more than 50% of the vote to win a primary outright. If no one clears that bar, the top two finishers meet in an Aug. 25 runoff. With several crowded fields, runoffs are likely.

The state is deeply red. Donald Trump won here with about 66% of the vote in 2024, and no Democrat has won a statewide federal race in years. So in most of these contests, the Republican primary is the real fight.

Governor: A Crowded Scramble

This is the marquee race. Gov. Kevin Stitt is term-limited, so the seat is open for the first time since 2018. Nine Republicans are running.

Attorney General Gentner Drummond led for most of the past year. He had the most money, the best name recognition, and a steady edge in poll after poll. For a while he looked close to winning the nomination outright.

Then the race tightened. A late-May poll showed a near four-way tie, with former state Sen. Mike Mazzei, Drummond, businessman Chip Keating and former House Speaker Charles McCall all bunched within a few points. That kind of split makes an Aug. 25 runoff very likely, and it leaves the second runoff spot wide open.

On the Democratic side, House Minority Leader Cyndi Munson is the only candidate. She will wait for the Republicans to sort themselves out. Whoever wins the GOP nod will be the heavy favorite in November, because no Democrat has been elected governor of Oklahoma since 2006. The betting markets back that up. Polymarket gives the Republican nominee about a 92% chance to win the seat in November, whichever candidate survives the primary. So the governor election betting odds that matter are the ones inside the GOP field, not the general.

Senate: An Open Seat and a Trump-Backed Front-Runner

Here is the biggest twist from what many expected. This seat was supposed to be a routine reelection run for Markwayne Mullin. Instead, Mullin resigned in March to become secretary of homeland security. Gov. Stitt appointed Alan Armstrong to hold the seat, but state law bars an appointee from running for a full term. So the seat is open.

Rep. Kevin Hern moved fast. The Tulsa-area congressman gave up his House seat to run, and President Trump endorsed him early. That endorsement made Hern the clear front-runner in a five-way Republican field. The open question is whether he tops 50% on June 16 or gets pulled into a runoff.

Several Democrats are running for their party's nod, including former nonprofit executive Jim Priest. But the math is steep. No Democrat has won a U.S. Senate race in Oklahoma since 1990, and the prediction markets price the seat accordingly. Polymarket and Kalshi both treat the Republican as a heavy favorite to hold it. So the Senate odds drama is not which party wins. It is whether Hern clears 50% on June 16 or gets dragged into an Aug. 25 runoff.

The House: One Open Seat, Four Safe Incumbents

Hern's exit created the most interesting House race. His 1st District seat, based in Tulsa, is now open. The Republican primary drew 11 candidates, the largest field in the district's history. Trump endorsed Tulsa pastor Jackson Lahmeyer, and other contenders include Corporation Commission Chair Kim David and state Rep. Mark Tedford. The district is safely Republican, so the GOP primary, and a likely runoff, will decide it.

The other four seats look quiet. Republicans Josh Brecheen in the 2nd, Frank Lucas in the 3rd, Tom Cole in the 4th and Stephanie Bice in the 5th are all running for reelection. Cole chairs the powerful House Appropriations Committee. All four won their last races by comfortable margins, and all are favored to win again. The House of Representatives odds in Oklahoma start and end with the open Tulsa seat.

What the Odds Say

Here is the betting picture. The November races are barely contests. On Polymarket, the Republican is about a 92% favorite to win the governorship, and the open Senate seat sits in the same safe-Republican range. Kalshi runs the same kind of party-winner markets, and its map puts Oklahoma in the top safe tier, where one side is given a 90%-plus chance. Every House seat reads the same way. Oklahoma is that red.

That moves all the suspense to June 16 and the August runoffs, which is where the real betting interest lives. The governor's race is the one to watch, a four-way scramble where polls show four Republicans bunched together and a single runoff slot could turn on a few thousand votes. The open Tulsa House seat is next, an 11-way primary with Trump's endorsement in play. For readers who follow election odds in Oklahoma, the primary is the main event, not the general.

One more item sits on every ballot. State Question 832 asks voters whether to raise the state minimum wage to $15 an hour by 2029. Any registered voter can weigh in on it, even those who skip the party primaries.

The Bottom Line

Oklahoma rarely produces November drama, and 2026 looks no different. The winners will almost certainly be settled this summer.

Watch three things. Can Drummond avoid a runoff, or does the four-way scramble drag him into August? Does Hern clear 50% for the Senate? And who survives the 11-way fight for Hern's old Tulsa seat?

For the latest election odds, the next dates that matter are June 16 and, if needed, Aug. 25. Oklahoma's general election is Nov. 3, 2026.