30% — Republican Presidential Nominee 2028: J.D. Vance
Polymarket 30% · 1 contracts · $11K volume · medium confidence
Updated 2026-06-08 06:13:29 UTC

Why this matters:
J.D. Vance is currently priced at 39% probability of becoming the Republican presidential nominee in 2028, making him the frontrunner across prediction markets. This reflects his position as Vice President and typical advantages of an incumbent administration's heir apparent, but also genuine uncertainty about whether he will ultimately secure the nomination. The probability reflects tension between his institutional backing and consolidation of Republican support versus potential challenges from other candidates, primary dynamics, or unforeseen political developments over the next 18 months. The nomination will be determined through the 2028 primary season and Republican National Convention, with key early contests in Iowa and New Hampshire likely to clarify frontrunner status significantly. Current market pricing suggests meaningful but not dominant confidence in his nomination prospects.

Key factors:
- J.D. Vance holds the Vice Presidency, which historically provides substantial advantages for securing a party's presidential nomination when an incumbent president is term-limited
- Alternative candidates including Marco Rubio (21¢), Tucker Carlson (7¢), and Donald Trump Jr. (3¢) collectively command 31% probability, indicating fragmentation rather than coalescing support around a single challenger
- Trading volume on the Vance contract ($23,251 in 24h volume) is the second-highest among Republican nominee contracts, suggesting active reassessment and genuine disagreement among market participants
- No scheduled primary elections or major clarifying events occur until late 2027, meaning the probability may shift substantially based on interim political developments, endorsements, or candidate announcements
- The 2-point spread between the Polymarket (39¢) and Kalshi (37¢) contracts on Vance suggests minimal arbitrage opportunity and relatively consistent pricing across venues

Contracts:
- Republican Presidential Nominee 2028: J.D. Vance — 30¢ Polymarket $11K (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: 2026-06-08T05:20:09.588Z*

By SimpleFunctions — https://simplefunctions.dev/

Cite as: "30% per prediction markets (SimpleFunctions, June 2026)"
Canonical: https://simplefunctions.dev/answer/republican-presidential-nominee-2028-jd-vance
Full data: https://simplefunctions.dev/api/public/query?q=Republican%20Presidential%20Nominee%202028%3A%20J.D.%20Vance
Provider: SimpleFunctions — https://simplefunctions.dev