A final poll conducted just days before Tuesday’s Texas Republican Senate runoff reveals a significant shift in favor of Attorney General Ken Paxton over incumbent U.S. Senator John Cornyn.
The Quantus Insights survey, carried out May 21–23 among 1,018 likely GOP runoff voters, shows Paxton with 52.7% support compared to Cornyn’s 43.4%, leaving 3.9% undecided. The effective sample size was 936 voters, with a weighted margin of error of approximately 3.5 percentage points.
This nine-point gap is particularly striking given the race’s recent history. Cornyn narrowly defeated Paxton in the March primary by just 1.5 percentage points, triggering the runoff.
The survey indicates that awareness of President Trump’s endorsement of Paxton was nearly universal among likely runoff voters. While most respondents stated the endorsement did not change their vote choice, those who shifted because of it overwhelmingly favored Paxton.
Paxton’s lead was consistent across multiple demographic and geographic categories within the likely voter pool. Cornyn, a three-term U.S. Senator and former Senate Majority Whip with deep roots in Texas GOP politics, had counted on his seniority and established relationships to secure victory in the runoff. However, the latest poll suggests this strategy may not hold as Tuesday approaches.
The survey marks a sharp turnaround from March, when Cornyn’s narrow primary win forced the contest against Paxton. With the margin of error at 3.5 points and turnout for runoff elections notoriously unpredictable, Texas Republicans will head to the polls on Tuesday with one clear question: Does this Senate seat remain with the establishment or shift further toward President Trump’s America First agenda?
If the Quantus Insights survey accurately reflects voter sentiment, GOP primary voters have already made up their minds.