Republican Secretary of State Michael Adams, who pushed successfully for expanded voter access, won his Primary against two candidates, including one who cast doubt on the integrity of elections.
The November General Election will be closely watched for signs of the mood of conservative voters.
GOP voters say they are basing decisions in the May 16 Primary mostly on which Republican would pose the toughest challenge to the Democratic incumbent.
The GOP candidates also delved into a range of issues including education, tax-and-spending priorities and gun rights.
Awaiting the Primary winner will be Democratic Gov. Andy Beshear, who has received consistently high voter approval ratings.
The back-and-forth reflects an increasingly combative contest between Kelly Craft and Daniel Cameron.
Beshear’s strong showing in the poll may be attributable to his approval rating, which sits at 61%.
Cameron’s lead expands when breaking down key Republican Primary constituencies.