# Democrats gain edge in Senate race, prediction markets show

> Traders on betting platforms now give Democrats a 55-59% chance of flipping the Senate this November.
- Title: Democrats gain edge in Senate race, prediction markets show
- Summary: Traders on betting platforms now give Democrats a 55-59% chance of flipping the Senate this November. Prediction markets now favor Democrats to win Senate…
- Keywords: senate, democrats, republicans, prediction markets, kalshi, polymarket, 2026 midterms, donald trump, gas prices, iran war, congressional elections, business
- Source: CNBC — https://cnbc.com/2026/09/16/prediction-markets-say-democrats-are-slightly-favored-to-win-senate.html
- Author: Davis Giangiulio
- Published: 2026-09-16T14:51:36+00:00
- Read time: 1 min
- Topics: senate, democrats, republicans, prediction markets, kalshi, polymarket, 2026 midterms, donald trump, gas prices, iran war, congressional elections, business
## Democrats now favored for Senate
Prediction market traders give Democrats a 55-59% chance of winning Senate control. This marks close to their best odds yet for flipping the chamber.
## Republicans defending tough map
The GOP holds 22 of the 35 Senate seats up for election. Democrats must flip seats in states Trump won by 10% or more, including Alaska, Texas, and Ohio.
## Iran war shifted the odds
Before the Iran war started on Feb. 28, Republicans had 60% odds to keep the Senate. Rising gas prices after the war began drove down Trump's approval.
## GOP recovered over the summer
Democratic odds topped Republican odds in April, but GOP chances recovered in May and summer. The U.S. and Iran de-escalated the war, easing gas price pressure.
## Energy prices hurt Republicans again
Oil is now above $100 per barrel, gas is over $4 a gallon nationally, and diesel prices hit all-time highs. Traders expect gas prices to reach new peaks this year.
## Polls show Democratic momentum
A New York Times/Siena poll this week showed likely voters favoring Democratic candidates by close to 9 percentage points nationwide.
## Key takeaway

Prediction markets now favor Democrats to win Senate control, driven largely by high gas prices and Trump's declining approval ratings.