29% — Will Congress ever override Trump's veto
Leader: Before Jan 20, 2029 at 29% · Kalshi 29% · 2 contracts · $0 volume · low confidence
Updated 2026-07-09 21:47:09 UTC

Tracks the leading outcome in a winner-take-all prediction market set with 2 outcomes.

Why this matters:
This represents the likelihood that Congress will muster a two-thirds majority in both chambers to overturn a Trump veto before January 20, 2029. Veto overrides are historically rare—only about 7% of presidential vetoes are overridden—and require substantial bipartisan consensus. The current 29% probability reflects uncertainty about both the frequency and type of vetoes Trump issues and whether either party will have sufficient motivation to override them. Key drivers include the composition of Congress, the partisan salience of specific bills being vetoed, and whether any vetoes affect widely-supported legislation. The market has priced lower odds for an override before 2027 (10%) compared to the full 2029 window, suggesting traders view the probability as more likely in the latter half of a potential Trump presidency. Major catalysts would include actual vetoes of significant bipartisan bills in the coming months, which would provide concrete test cases for override likelihood.

Key factors:
- Override success requires 67 votes in Senate and 290 in House; current Congress composition affects feasibility
- Historical veto override rate is approximately 7%, providing baseline for how rare these outcomes are
- Type of legislation matters significantly—overrides more likely on widely-popular bills with genuine bipartisan support
- Political polarization affects willingness to cross party lines on major presidential disagreements
- Early vetoes in 2026-2027 would provide direct evidence; their topics and voting patterns would indicate trajectory toward 29% or elsewhere

Contracts:
- Will Congress ever override Trump's veto?: Before Jan 20, 2029 — 29¢ Kalshi $0 (weight 50%)
- Will Congress override Trump's veto before 2027?: Before 2027 — 10¢ Kalshi $0 (weight 50%)

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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: 2026-07-09T21:20:50.957Z*

By SimpleFunctions — https://simplefunctions.dev/

Cite as: "29% per prediction markets (SimpleFunctions, July 2026)"
Canonical: https://simplefunctions.dev/answer/vetooverride
Full data: https://simplefunctions.dev/api/public/query?q=Will%20Congress%20ever%20override%20Trump's%20veto
Provider: SimpleFunctions — https://simplefunctions.dev