Harris isn't buying the conversion and, to make his point, he won't even call Koster a real Democrat.

Harris said Sen. Koster dodged a vote on school vouchers in February. The bill in question would give tax credits to special education students to attend private or religious schools.

Koster didn't cast a vote the day the bill came up in committee. His campaign says he missed it because he was working on other legislation.

"Is he for the bill or is he against the bill? I think all Democrats want to know the answer to that question," Harris asked during a campaign stop in Springfield on Wednesday.

Koster's campaign told KY3 News that "no politician should be closed minded to the debate over providing quality special education for disabled children." In earlier comments, he appeared to favor the legislation. Harris is opposed to using any public money for private schools.