Will John Thune win the 2028 Republican presidential nomination?

Reference class: sitting Senate Majority Leaders seeking their party's presidential nomination in the modern era — base rate of winning is extremely low (near 0%; e.g., Dole 1996 is the rare exception, and most majority leaders never win nominations). Adjustments: (−) Thune has not signaled a 2028 run and lacks a national campaign apparatus or strong base in the MAGA-dominated GOP primary electorate; (−) the 2028 field is expected to be led by Trump-aligned figures (Vance, DeSantis, etc.) who poll far ahead; (−) Thune's past frictions with Trump make him unpopular with the activist base. Market price (~0.7%) aligns with this assessment. Modest floor for tail scenarios (brokered convention, frontrunner collapse).

Thune is Senate Majority Leader, not a declared presidential candidate, and has shown no signs of running. The GOP 2028 field is dominated by Vance, DeSantis, and other higher-profile figures. Market price of 0.7% is already very low and roughly fair; no contrarian case justifies going higher.

Market pricing at 0.7% reflects the field's reality: Thune is Senate Majority Leader with no presidential campaign infrastructure, no notable polling presence, and faces a crowded 2028 field likely dominated by DeSantis, Trump-aligned figures, or other higher-profile contenders. His odds are extremely low.

The market price of 0.7% serves as a well-anchored prior, reflecting that Thune is a very long shot for the 2028 Republican nomination. He lacks the populist appeal, national profile, and grassroots activist base that have dominated GOP primary selection in recent cycles. However, his status as a senior senator and major party figure provides slightly more institutional viability than a random politician, warranting a modest adjustment upward to 0.9%. Without hard evidence of significant shifts in his candidacy prospects, endorsements from major party figures, or dramatic changes to the primary field, the market's assessment remains sound.

John Thune became Senate Majority Leader in January 2025, which gives him a prominent platform but historically few Senate leaders have successfully captured presidential nominations. The market price of 0.70% is a useful anchor but can reflect thin liquidity and idiosyncratic sentiment rather than pure probability. Key uncertainties: (1) The 2028 Republican field is wide open and will likely include governors, former Trump figures, and others with stronger populist credentials or executive experience; (2) Thune is seen as an establishment figure, which is a disadvantage in post-Trump GOP primaries; (3) He will be ~67 in 2028, not a disqualifying age but not an advantage; (4) His vote to certify the 2020 election and occasional disagreements with Trump could hurt him in a base that remains broadly Trump-loyal; (5) There is a recency bias risk — his current prominence as Majority Leader may make him seem more likely than he is. However, legislative leaders do occasionally run credible campaigns, and circumstances could shift. The market price of ~0.7% seems roughly calibrated; I'd nudge slightly above given the long time horizon and genuine uncertainty, but keep it low given structural disadvantages in a Trump-aligned primary electorate.