Liberty For All executive director Preston Bates announced the switch in a statement Thursday, the same day an ad began airing criticizing GOP congressional hopefuls Alecia Webb-Edgington and Gary Moore.

The group has spent more than $500,000 to purchase airtime on Cincinnati and Louisville TV stations leading up to Tuesday's primary election.

Seven people are seeking the Republican nomination to replace retiring U.S. Rep. Geoff Davis who is calling it quits after 10 years in Washington. Massie, Moore and Webb-Edgington are the presumed front-runners in the race.