The Texas Republican Senate runoff is the cleanest snapshot yet on prediction markets of the Trump endorsement wave that has rolled through GOP primaries over the last few weeks.
Once President Donald Trump backed Ken Paxton for the Texas Senate, prediction markets didn’t just move. Traders pushed Paxton to a dominant price that suggests they think the race is basically over. That came after the same broader pattern already seen in places like Louisiana and Kentucky. The Texas GOP Senate runoff is Tuesday between Paxton and incumbent Sen. John Cornyn and Paxton is currently a 95% favorite on Kalshi to get the nomination.
Trump picks a side, and the challenger gets a surge. The incumbent suddenly looks like he is running uphill in a party where Trump loyalty has become the real ballot line.
Prediction markets nail Trump wins
Trump has systematically targeted Republican candidates who have defied him throughout his time as president. But the GOP primaries over the past two weeks have shown his true power in the Republican electorate.
Markets were clear that they believed Louisiana Sen. Bill Cassidy would place third among candidates in the running. In Saturday’s election, Cassidy did not qualify for a runoff, losing to Trump-backed Rep. Julia Letlow and John Fleming.
Traders were a little less sure in a Kentucky House race. But after Cassidy’s loss Saturday, traders eventually flipped and called incumbent Rep. Thomas Massie’s loss to Trump-backed Ed Gallrein on Tuesday. And even before Massie’s loss was official, Trump endorsed Paxton in the Texas Senate race, causing prediction markets to all but call that race.
Now, Axios reports Trump is already considering who to target in the 2028 primaries.
Will Trump’s power translate to November?
Trump’s power over Republican primaries is not the same thing as Republican strength in the general election. Senate Republicans are already upset at his endorsements, suggesting his candidates could cost them in November. And independents are among those pushing him to his lowest approval ratings as president.
Prediction markets are already pointing in that direction. Trump’s endorsement wave is helping nominate candidates who are highly effective in a primary, but often much weaker once the race is back in front of independents and soft Republicans in November.
After he endorsed Paxton, markets for the Texas Senate general election against Democrat James Talarico tightened to a near toss-up. It is the same tension that runs through the whole 2026 Senate map.
Crystal Ball Senate view
Polls and The Center for Politics Sabato’s Crystal Ball suggest it will be a tight race to control the Senate in the 2026 midterm elections.
Sabato’s Crystal Ball reads that the Senate is still in play, but Democrats don’t have a clean path and will need to steal some seats. The Crystal Ball suggests it will break to 46 Democrats, 51 Republicans, with three toss-up seats. That would leave Republicans in control of the Senate, no matter what happens in those toss-up states.
How it lays out the 2026 battleground map:
- Michigan: Toss Up (Currently: Democrat)
- North Carolina: Toss Up (Currently Republican)
- Maine: Toss Up (Currently Republican)
- Georgia: Leans Democrat (Currently Democrat)
- Ohio: Leans Republican (Currently Republican)
- Alaska: Leans Republican (Currently Republican)
- Texas: Likely Republican (Currently Republican)
Where the markets differ
While prediction markets have the Republicans keeping the Senate in the low-50s on the broad question contract, the state-by-state contracts suggest a different story. Traders are painting a Senate map that shows an easy path for Democrats to take the Senate.
While these could change as volume turns from primary elections to November, these are the reads on Kalshi and Polymarket at the moment:
- Michigan: Markets are mid-70s for a Democrat win
- Georgia: Markets are low- to mid-80s for a Democrat win
- Maine: Markets are in the 70s for a Democrat win
- Alaska: Markets are at 60% for a Democrat win
- North Carolina: Markets are at 84% for a Democrat win
- Ohio: Markets are mid-50s for a Democrat win
- Texas: Markets are mid-50s to remain Republican
If all those contracts hold, that’s a solidly Democratic Senate in 2027.
What Texas Senate prediction markets pricing says
The paradox exists because the Senate isn’t one race. It’s a bundle of state-specific contests with different electorates, different incumbents, and different degrees of Trump exposure. A lot has to go right for the prediction markets to nail all of the separate state elections.
Trump’s endorsement wave is real, and it is reshaping Republican primaries in a way the prediction markets have been quick to understand. But the same wave may be creating the kind of general election nominee profile that puts the Senate at risk for the GOP. Texas is the clearest example, because Paxton’s strength in the runoff could turn a GOP hold into a November fight.
Prediction markets have nailed Trump’s primary winning streak. They are also pricing in his unpopularity in November contracts and suggesting Democrats have a clear path to Senate control.
