94% — Will exactly 2 Senate Republican members lose their primary in 2026
Kalshi 94% · 1 contracts · $65 volume · low confidence
Updated 2026-06-26 07:47:39 UTC

Why this matters:
This market estimates a 21% chance that exactly two Senate Republicans will lose their primary elections in 2026. Primary challenges to incumbents depend on factors like district/state ideology, fundraising strength, endorsements, and candidate quality. Historical context matters: Senate Republican primary losses have been relatively rare in recent cycles, though they do occur during waves of dissatisfaction with establishment members. The probability reflects expectations that while primary challenges will happen, the specific outcome of exactly two losers is neither highly likely nor highly unlikely. Resolution requires tracking all Senate Republican primaries through the 2026 election cycle, with most contests occurring between March and September 2026. Related markets suggest uncertainty about the total number of Republican primary losses, with traders pricing lower odds for outcomes of 4+ Senate losses (9 cents) but higher odds for exactly 1 loss (29 cents), indicating a relatively flat distribution across different scenarios.

Key factors:
- Current Senate Republican incumbents facing well-funded, ideologically-motivated primary challengers and their polling performance relative to primary voters
- National political environment and any major scandals or legislative votes that might energize specific primary constituencies between now and primary season
- Endorsement patterns from Trump, state party officials, and major outside groups, which have historically influenced Republican primary outcomes
- Primary election calendar timing and field fragmentation—whether multiple challengers split anti-incumbent votes or consolidate support
- Historical baseline: Senate Republican primary defeats averaged roughly 1-2 per cycle in recent decades, making exactly 2 neither extreme nor baseline

Contracts:
- Will exactly 2 Senate Republican members lose their primary in 2026?: 2 — 94¢ Kalshi $65 (weight 100%)

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## Methodology

SimpleFunctions aggregates live YES-side prices from Kalshi and Polymarket contracts bound to this question. For binary topics the headline is the liquidity-weighted mid-price (weight = log(1 + 24h volume) × freshness, where freshness is 1.0 if updated <24h, 0.7 if <7d, 0.4 otherwise). For multi-outcome (winner-take-all) topics the headline is the current leader's price — disjoint outcomes are never arithmetically averaged. Snapshots refresh every 5 minutes during market hours.

## SF Signal

- SF Index, regime, and 30d Brier calibration are computed separately and surfaced at https://simplefunctions.dev/admin/calibration.
- No SimpleFunctions index / regime / calibration signal is bound to this topic yet — the headline above is market-derived only.

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*Last verified: 2026-06-26T07:20:50.987Z*

By SimpleFunctions — https://simplefunctions.dev/

Cite as: "94% per prediction markets (SimpleFunctions, June 2026)"
Canonical: https://simplefunctions.dev/answer/loseprimarysenater
Full data: https://simplefunctions.dev/api/public/query?q=Will%20exactly%202%20Senate%20Republican%20members%20lose%20their%20primary%20in%202026
Provider: SimpleFunctions — https://simplefunctions.dev