The Republican nominee for Governor in Oklahoma expressed skepticism of childhood vaccinations in a speech earlier this year, aligning himself with a fringe movement that equates immunization with government overreach.

At an appearance before a conservative political forum this past February, Tulsa businessman Kevin Stitt said he personally did not vaccinate some his own kids and opposed legislation that would require vaccinations for children if they wanted to attend public schools.

“I believe in choice,” Stitt said, “And we’ve got six children and we don’t vaccinate, we don’t do vaccinations on all of our children. So we definitely pick and choose which ones we’re gonna do. It’s gotta be up to the parents, we can never mandate that. I think there’s legislation right now that are trying to mandate that to go to public schools, it’s absolutely wrong. My wife was home schooled, I went to public schools, our kids go to Christian school, and that’s back to a parent’s choice.”

Stitt’s comments raise the specter that Oklahoma could water down immunization laws should he be elected the state’s governor this fall. They also place him within a growing fringe of politicians who have, in recent years, expressed skepticism over the prevalence of childhood vaccinations—a group that includes President Donald Trump himself.

“Kevin believes the topic of vaccinations is a serious decision that should be made by parents in consultation with their pediatricians,” said Donelle Harder, Stitt’s spokeswoman. She said that Stitt did not believe that vaccinations cause harmful medical side effects —an oft-argued and scientifically baseless claim from vaccine skeptics. The “root of his decision,” she said was the desire for parental choice

Such a position puts Stitt on the opposite side of public health advocates who have warned that immunizations must be a social contract in order to be medically effective. Anecdotal and scientific data has shown a direct correlation between vaccination hesitancy and the rise of diseases like measles.

Under Oklahoma law , children are required to have a number of immunizations in order to attend public school. But the state, like others, offers medical, religious and personal exemptions.

Harder said that Stitt was not interested in changing current law. But Lawmakers in the state have attempted to craft legislation that would reduce the number of parents using these exemptions: either be limiting their availability or by adding measures to encourage parents to vaccinate their kids (such as requiring them to watch videos about diseases that can result from a lack of immunization).

One such bill—which would have limited exemptions to only those that were medical—was making its way through the Oklahoma state house at around the same time that Stitt appeared at the Oklahoma Conservative Political Action Committee, a deeply socially conservative organization.

The bill, filed by Senator Ervin Yen, (R-Oklahoma City), made it out of committee but not to the Senate floor. In the process, Yen became the target of an intense and ugly smear campaign, with mailers going around the state picturing him alongside Hitler, Mao and Mussolini with the words: “Don't believe in medical choice? These people didn't, either.”

“That came from some very far right conservatives in Oklahoma who think what I’m trying to do is big government,” Yen told The Daily Beast. “I’m not. I’m trying to make the public safe.”

Yen told The Daily Beast that, as of now, his bill was “dead” but that he would seek any opportunity available to him to increase vaccinations in Oklahoma, even if it meant working against Stitt, should Stitt be elected.

“In my opinion,” Yen said, “he is absolutely wrong. If you have a child who is immunocompromised and can’t be vaccinated you want the other kids around your child to be vaccinated so he or she doesn’t get one of these contagious diseases that they can die from.”

Stitt will face Democratic nominee Drew Edmondson, the state’s former attorney general. There is scant public polling on their race. The most recent survey, taken back in July—well before the nominations were secured—had it as a tossup.