South Carolina Republican Senate special primary winner?

Kalshi Expiration: August 11, 2027 Updated: August 15, 2026 Elections Primaries

By Ken So, Octagon Research Editor

Short Answer

Both the model and the market overwhelmingly agree that Darline Graham is most likely to win the South Carolina Republican Senate special primary, with only minor residual uncertainty.

1. Executive Verdict

Darline Graham appears favored despite limited new runoff data.
Graham and Ralph Norman advanced in the August 11 special primary.
The August 25 runoff has no reported endorsements from Mace or McMaster.

Who Wins and Why

Outcome	Market	Model	Why
Darline Graham	86.0%	91.4%	Darline Graham leads with strong support in current polling, making her the likely winner.
Ralph Norman	14.0%	5.6%	Ralph Norman remains a distant challenger, trailing significantly in available support.

Current Context

On August 11, 2026, no candidate secured more than 50 percent of the vote in the South Carolina Republican Senate special primary, preventing an outright win [^] [^] [^] [^] [^] [^] . 25 in GOP Senate primary runoff - Statehouse" data-source-lanes="traditional">[^]^{[^]}^{[^]}^{[^]}^{[^]}. The primary will proceed to a runoff election on August 25, 2026, between Senator Darline Graham and U.S. Representative Ralph Norman ^{[^]}^{[^]}^{[^]}. Senator Graham received 32.71% of the vote, while Representative Norman garnered 24.63% of the vote; both were the top two vote-getters and will contest the runoff ^{[^]}^{[^]}^{[^]}.

Senator Lindsey Graham's death necessitated the special election. The special election was initiated following the death of U.S. Senator Lindsey Graham on July 11, 2026 ^{[^]}^{[^]}^{[^]}^{[^]}^{[^]}. Darline Graham, the late Senator's sister, had been appointed to serve the remainder of his term ^{[^]}^{[^]}^{[^]}. The winner of the August 25 Republican runoff will advance to face Democratic nominee Dr. Annie Andrews in the general election on November 3, 2026 ^{[^]}^{[^]}^{[^]}.

2. Market Behavior & Price Dynamics

Historical Price (Probability)

Outcome probability

Date

This contract shows a clear upward trend, with the probability of a 'YES' outcome moving from a starting price of 63.0% to a current level of 86.0%. The market experienced significant volatility, trading within a wide range of 39.0% to 92.0%. A key inflection point occurred around the August 11 primary. Before the vote, the price saw a sharp, unexplained 10.0 percentage point drop on August 6. Following the primary, the contract established a new support level above 80.0%, with the post-election peak of 92.0% acting as near-term resistance.

The primary driver for price action was the result of the August 11 special primary. On August 12, news reports projected Darline Graham had secured the top spot for the runoff, causing an immediate 11.0 percentage point spike from 67.0% to 78.0%. This momentum continued through August 14, with another 9.0 point jump to 91.0% as the market fully priced in the official outcome, which placed Ralph Norman as the second-place finisher. The primary effectively resolved market uncertainty, repricing the contract from a competitive race to one with a clear frontrunner.

Total traded volume of over 2.8 million contracts indicates substantial market interest. Volume appears to have been highest during periods of uncertainty, such as the price dip around August 8. The lower volume seen after August 15 suggests that conviction firmed up after the primary results were known, with less speculative trading. The current price of 86.0% reflects strong market sentiment that the leading candidate from the primary will win the subsequent runoff.

3. Significant Price Movements

Notable price changes detected in the chart, along with research into what caused each movement.

Outcome: Ralph Norman

📉 August 14, 2026: 10.0pp drop

Price decreased from 19.0% to 9.0%

What happened: The primary driver of Ralph Norman's prediction market price drop was the official outcome of the South Carolina Republican Senate special primary on August 11, 2026. The results, publicly known by August 12, revealed that no candidate won outright, and Norman placed second with 24.63% of the vote, advancing to a runoff against Darline Graham (32.71%) scheduled for August 25, 2026 ^{[^]}. This confirmed Norman had not won the primary directly, leading to a significant reassessment of his likelihood of being the eventual "winner" and causing the price decline by August 14, 2026. Social media was irrelevant, as no evidence of related activity was found.

Outcome: Darline Graham

📈 August 12, 2026: 11.0pp spike

Price increased from 67.0% to 78.0%

What happened: The primary driver of the 11.0 percentage point spike in Darline Graham's prediction market price on August 12, 2026, was the official news reporting of the South Carolina Republican Senate special primary election results. On August 12, 2026, major news outlets projected that Darline Graham, having secured approximately 32.7%–33% of the vote, finished first and advanced to a runoff election against Ralph Norman ^{[^]}^{[^]}^{[^]}^{[^]}. This confirmation of her leading position and advancement to the runoff, establishing her as the frontrunner for the nomination, coincided directly with the prediction market price movement ^{[^]}^{[^]}^{[^]}. Social media was irrelevant, as no specific activity or viral narratives were found to have driven this price change ^{[^]}.

📉 August 06, 2026: 10.0pp drop

Price decreased from 58.0% to 48.0%

What happened: The provided web research offers no evidence of Darline Graham experiencing a 10.0 percentage point drop in support related to a specific catalyst event on August 6, 2026 ^{[^]}. Instead, news reports describe Darline Graham as a leading candidate who advanced to an August 25 runoff following the August 11, 2026, special Republican primary ^{[^]}^{[^]}^{[^]}^{[^]}^{[^]}. Given the absence of supporting information for the described market movement, the primary driver cannot be identified based on the available sources ^{[^]}. Consequently, social media activity was irrelevant as a primary driver, contributing accelerant, or noise for this unsupported market event.

4. Market Data

View on Kalshi →

Contract Snapshot

This market determines the winner of the South Carolina Republican Senate special primary. A "Yes" contract for a specific candidate will resolve to $1 if that candidate wins the primary, while a "No" contract for that candidate will resolve to $1 if they do not win. The market opens on August 25, 12:00 am EDT, with a maximum payout date of August 11, 2027.

Available Contracts

Market options and current pricing

Outcome bucket	Yes (price)	No (price)	Last trade probability
Darline Graham	$0.87	$0.14	86%
Ralph Norman	$0.15	$0.86	14%

Market Discussion

No single winner emerged from the August 11, 2026, South Carolina Republican special Senate primary, as no candidate achieved a majority ^{[^]}^{[^]}^{[^]}^{[^]}^{[^]}^{[^]}^{[^]}. Consequently, Darline Graham, who received approximately 32.7% of the vote, and U.S. Representative Ralph Norman, with about 24.6%–24.7% of the vote, advanced to a runoff election scheduled for August 25, 2026 ^{[^]}^{[^]}^{[^]}^{[^]}^{[^]}^{[^]}^{[^]}^{[^]}.

5. Trader Dashboard

A deterministic, per-market integrity scorecard computed from order-book and price data. Higher is better for Trader Trust, Liquidity, Move Quality and Resolution; higher means more risk for Quote Risk and Avoid Risk.

Darline GrahamPrimaryTrader Trust—Liquidity—Move Quality—Resolution—Quote Risk—Avoid Risk—

Move Quality—No significant movehigh confidence

Factor

Pamela EvetteTrader Trust—Liquidity—Move Quality—Resolution—Quote Risk—Avoid Risk—