Will Darline Graham Nordone win Richland County in the South Carolina Special Senate Primary runoff?

Thesis

• Outside view: runoff favorites leading after the first round win most of the time, but upsets in low-turnout special-election runoffs are not rare (10-20%), capping justified confidence below the market's 93.5%.
• Inside view is thin: I lack verified polling, first-round margins, or endorsement data for this specific Richland County race, so I anchor mostly on the reference class rather than case-specific signal; the fact that the question is framed around her suggests she is the perceived frontrunner, which is modest signal.
• Time-decay is minimal (3 days to close, election imminent), so late-scandal risk is compressed but not zero; low 24h volume ($7.2k) means the 93.5% price may partly reflect thin liquidity and informed local money rather than a robust consensus, plausibly explaining the gap to my estimate.
• My independent estimate sits a few points below the market because systematic base rates for heavy favorites argue against 93%+ absent confirmed polling dominance, which I cannot verify.

Base rate

First-round leaders and polling favorites in U.S. primary runoffs historically win roughly 70-85% of the time, with heavily favored candidates in low-salience local runoffs resolving as expected at the higher end.

What would prove this wrong

A late-breaking endorsement reversal, scandal, or a verified poll showing her trailing would move this sharply; conversely, confirmed double-digit polling leads would push me toward the market's 93%+.

Settlement

Resolved YES on 26 Aug 2026 · settlement source