2026 Balance of Power: R Senate, R House
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Tracked on one venue, with Crossbook's own call on the record.
Bid/ask midpoint · retrieved 2026-10-29T19:25:26.934Z. Venue quote-update time is unavailable. Readings can be asynchronous.
6.5%bid 6.0% / ask 7.0%24h volume $1.2M · liquidity $5.3Mas of 29 Oct, 19:25 UTCView on PolymarketPrice, last 60 days
Crossbook forecast
- 19.3%against a market price of 7.5% at the timeOpen
Logged 25 Oct 2026, 15:01 UTC
- The base rate already encodes the midterm penalty: unified control survives only about 4 in 10 times post-WWII, and the last three such midterms (2010, 2018, 2022) all saw the president's party lose at least the House.
- The Senate map structurally favors Republicans: Democrats need a net gain of four with Vance breaking ties, defending 13 seats while the GOP defends 22 — but the retrieved toss-up list (AK, IA, KS, ME, OH, TX are GOP-held; only MI is Dem-held) means Democrats must win roughly four of six GOP toss-ups plus hold Michigan, so GOP Senate retention is more likely than not even in a bad environment.
- Signal of a hostile environment for the president's party: Democrats lead in Iowa (Turek +2) and Ohio (Brown +6), and Texas is tied — red-state Senate races should not be competitive in a neutral year, which cuts against the GOP holding both chambers.
- House signal also points against the GOP: 16 of Cook's 21 toss-ups are Republican-held, meaning the GOP is defending far more exposed turf, consistent with the House being the more likely chamber to flip.
- Because both chambers respond to the same national environment, the joint outcome is positively correlated — this isn't the product of independent probabilities; the joint lands near P(GOP holds House) plus a small credit for scenarios where a modest Democratic environment flips the House but the Senate map saves the GOP, which is why I land below the base rate but not near zero.
- Missing generic-ballot and presidential-approval data and incomplete race-level polling cap how far I move from the base rate; the competitive-red-state polls are genuine signal but partial.
What would change it: Late-cycle polling showing Republicans regaining leads in Iowa, Ohio, and Texas and/or a generic-ballot shift toward the GOP would push this back toward or above the base rate.
t-0272
Context
Polymarket prices this at 6.5%. No verified equivalent is currently listed on the other venue, so there is no cross venue comparison on this page.
Volume over the last 24 hours is heavy, at about $1,230,959 on the busier venue. It closes in 5 days. Prices this close to resolution move on news rather than on reassessment.
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