3% — Republican Presidential Nominee 2028
Polymarket 3% · 1 contracts · $21K volume · medium confidence
Updated 2026-06-08 06:12:42 UTC

Why this matters:
Marco Rubio is priced at 21% probability to win the 2028 Republican presidential nomination, reflecting market expectations that he faces meaningful but not dominant odds against other potential candidates. This estimate is shaped primarily by his current position as Secretary of State, which provides visibility and establishment credibility but may constrain his ability to campaign actively. The nomination process typically hinges on early contests in Iowa and New Hampshire, scheduled for early 2028, where candidate performance and momentum often reshape expectations significantly. Key uncertainty exists around whether other figures—including those currently less visible in markets—might consolidate support or withdraw from contention as the primary season approaches, materially altering the distribution of probabilities among remaining candidates.

Key factors:
- Rubio's Cabinet position provides institutional platform but limits independent campaigning compared to full-time candidates
- Iowa caucuses and New Hampshire primary in early 2028 will be decisive testing grounds; early primary results historically shift nomination odds substantially
- No single candidate commands majority probability; the second-place finisher trades at 8%, indicating fragmented field and potential for support consolidation
- Candidate withdrawals or entries between now and voting could redistribute the 79% probability assigned to non-Rubio outcomes
- Market pricing reflects limited historical precedent for sitting Secretary of State securing their party's nomination without prior gubernatorial or Senate voting record

Contracts:
- Republican Presidential Nominee 2028: Ron DeSantis — 3¢ Polymarket $21K (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: 2026-06-08T05:20:08.355Z*

By SimpleFunctions — https://simplefunctions.dev/

Cite as: "3% per prediction markets (SimpleFunctions, June 2026)"
Canonical: https://simplefunctions.dev/answer/republican-presidential-nominee-2028
Full data: https://simplefunctions.dev/api/public/query?q=Republican%20Presidential%20Nominee%202028
Provider: SimpleFunctions — https://simplefunctions.dev