# Balance of Power: 2026 Midterms: R Senate, D House

> Liquidity-weighted aggregate at 34% across 1 contract — refreshed 7 min ago.

URL: https://simplefunctions.dev/odds/balance-of-power-midterms-r-senate-d-house
Updated: 2026-05-09T05:05:43.321Z
Category: general · Topic: election-2026
Status: active
Closes: 2026-11-03

## Headline

- Probability: 34% (liquidity-weighted across 1 contract)
- Venue: Polymarket (1 contract)
- 24h volume: $19K

## Bound contracts (1)

| Outcome | Price | 24h | Volume | Venue | Slug |
|---|---|---|---|---|---|
| 2026 Midterms: R Senate, D House | 34¢ | −1pp | $19K | polymarket | /markets/balance-of-power-2026-midterms-r-senate-d-house-polymarket-0x998bc71817b2d76921d1999ce0f3431cfd5945583667a371280ca2b430b0c06e |

## 30-day trajectory

| Day | Aggregate |
|---|---|
| 2026-04-09 | 37 |
| 2026-04-25 | 37 |
| 2026-05-01 | 39 |
| 2026-05-08 | 34 |

_17 days of price history captured. Each row is the daily mean of intraday 5-min captures._

## What moved the line

- 2026-05-06 · 2026 Midterms: R Senate, D House −4pp 39→35¢ · polymarket

## Analysis

This probability represents the likelihood that Republicans will control the Senate while Democrats retain control of the House following the 2026 midterm elections. The current 24% estimate reflects a significant disagreement between prediction markets, with Kalshi pricing the scenario at 46% while Polymarket values it at 16%—a 30-percentage-point gap suggesting unresolved market uncertainty. This outcome would require Republicans to gain Senate seats while Democrats successfully defend their House majority, a split outcome that historically occurs less frequently than unified government. The probability will adjust as economic conditions become clearer, campaign dynamics emerge, and seat-specific races develop detail through summer and fall. The November 2026 midterm election will provide final resolution, with early voting and exit polls potentially moving markets in late October.

### Key factors

- Current Senate composition and specific seat competitiveness in 2026 races, particularly in purple-state constituencies where split-ticket voting patterns would be necessary
- Economic performance through mid-2026, including inflation trajectory and consumer confidence measures that typically drive midterm results
- House district-level fundamentals: Democrats currently hold the chamber with a slim margin, requiring strong defensive performance in suburban and swing districts
- The 30-point gap between Kalshi and Polymarket suggests material disagreement on either House hold probability or Senate flipping odds that may reflect different modeling assumptions
- Turnout composition and demographic shifts between 2024 and 2026, particularly among youth and independent voters who influence both chamber outcomes

## Methodology

Probability is **liquidity-weighted** across all bound Kalshi/Polymarket contracts: Σ(price × volume) ÷ Σ(volume). 30-day trajectory uses the daily mean of intraday 5-min captures. 24h delta = today's mean − yesterday's mean. Movement events are ≥3pp daily moves in the last 7 days.

## How to use this data

- HTML: https://simplefunctions.dev/odds/balance-of-power-midterms-r-senate-d-house
- JSON: https://simplefunctions.dev/api/public/odds?slug=balance-of-power-midterms-r-senate-d-house
- Topic hub: https://simplefunctions.dev/predictions/election-2026

## License

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