SimpleFunctions
6 source contracts·Kalshi 6·refreshed just now·Closes Jan 20, 2029 · 923d

Will Marco Rubio defeat Gavin Newsom in the 2028 presidential election, with Gavin Newsom as the Democratic nominee and Marco Rubio as the Republican nominee

Liquidity-weighted aggregate sits at 6% across 6 Kalshi contracts.

Implied probability

6%
0%50%100%

Kalshi

6%

6 contracts

Polymarket

not bound

Cross-venue gap

single venue

24h move

no pin

24h volume

$67

6 contracts

Closes

Jan 20, 2029

923 days

30-day trend

0%50%100%-30d-3w-2w-1wtodayAggregate: 11% (19 days, 19 points)Aggregate: 11% on 2026-07-09
Aggregate of 6 contracts · 19d

Bracket families

5 clusters across 6 contracts.

These contracts were grouped by title similarity. The headline aggregate combines all clusters; verify the cluster you actually need before quoting a number.

Heads-up — heterogeneous clusters

The top two clusters share only 11% of their title tokens — “Will Alexandria Ocasio-Cortez defeat” vs “Will Jon Ossoff defeat Marco Rubio in the 2028 presidential election, with Jon Ossoff as the Democratic nominee and Marco Rubio as the Republican nominee”. The headline aggregate weights both, so the number on this page is meaningful only if the clusters resolve to the same question.

Cluster 1

Will Alexandria Ocasio-Cortez defeat

2 contracts$0

Cluster 2

Will Jon Ossoff defeat Marco Rubio in the 2028 presidential election, with Jon Ossoff as the Democratic nominee and Marco Rubio as the Republican nominee

1 contract$67

Cluster 3

Will Gavin Newsom defeat JD Vance in the 2028 presidential election, with Gavin Newsom as the Democratic nominee and JD Vance as the Republican nominee

1 contract$0

Cluster 4

Will JD Vance defeat Gavin Newsom in the 2028 presidential election, with Gavin Newsom as the Democratic nominee and JD Vance as the Republican nominee

1 contract$0

Cluster 5

Will Marco Rubio defeat Gavin Newsom in the 2028 presidential election, with Gavin Newsom as the Democratic nominee and Marco Rubio as the Republican nominee

1 contract$0

Analysis

This probability represents the chance that Marco Rubio defeats Gavin Newsom if both become their parties' 2028 presidential nominees. The 7% figure reflects market assessments that while Newsom securing the Democratic nomination is moderately plausible (24¢ implied probability), Rubio winning the general election against him is considered unlikely. The current level is driven by two main considerations: Newsom's relative strength in general-election matchups versus other potential Republican candidates, and historical patterns where incumbent-party nominees face headwinds after serving for extended periods. The biggest near-term catalyst will be the 2026 midterm results in November, which typically signal broader electoral trends and could shift perceptions of each candidate's viability. Additionally, any major economic data, foreign policy developments, or shifts in either candidate's political standing before the 2028 conventions would significantly alter these probabilities.

  • Newsom's 24¢ nomination probability implies markets see him as a credible but not heavily favored Democratic candidate, requiring Rubio to clear higher odds in a general matchup
  • Rubio's 23¢ Republican nomination probability suggests meaningful uncertainty about whether he secures the GOP nomination, directly capping the joint scenario's probability
  • Historical data shows general-election matchup polls 2+ years before the election have limited predictive power, but current head-to-head metrics between these candidates would inform traders
  • 2026 midterm performance will provide signals about national sentiment and either candidate's coattails, potentially shifting both nomination and general-election probabilities
  • Economic conditions and incumbent approval ratings between now and November 2028 are major variables that typically determine general-election outcomes

What moved the line

  • Jul 8Marco Rubio defeats Gavin Newsom5pp813¢ · Kalshi

Recently closed in election 2026

These markets stopped trading. Last odds and any captured outcome are shown above — full settlement detail lives at the venue.

More like this

Other questions in election 2026.

How we compute these odds

SimpleFunctions aggregates live prediction-market contracts from Kalshi and Polymarket. Each slug groups contracts that resolve on the same underlying event, identified by venue event_id.

For binary slugs, the headline probability is the liquidity-weighted mid-price across all bound contracts. For multi-outcome slugs (e.g. elections with 3+ candidates), the headline is the leader’s price; we never arithmetically average disjoint outcomes — that would produce a number with no real-world meaning.

Snapshots refresh every 5 minutes during market hours; daily aggregates are computed at 04:00 UTC. The 30-day sparkline is drawn from per-ticker daily means stored in market_indicator_daily; 24h delta and movement events are derived from the same source.

Last updated on this page: just now.