Mike Huckabee picked a fight Tuesday with his most formidable opponent yet. No, not Jeb Bush, Mitt Romney, Hillary Clinton, or Barack Obama—the former Arkansas governor is taking on Beyoncé.

In an interview with People magazine, the potential presidential hopeful launched an attack on the most powerful celebrity in the world, criticizing the Obamas for letting their daughters listen to her music. Huckabee said he was puzzled that the president and first lady “don’t see anything that might not be suitable for either a preteen or a teen in some of the lyrical content and choreography of Beyoncé, who has sort of a regular key to the door.”

Huckabee’s comments amplify criticisms of the singer in his new book, God, Guns, Grits and Gravy, in which he describes some of Beyoncé’s lyrics as “obnoxious and toxic mental poison.” The former Arkansas governor also expressed concern about the pop star’s marriage to Jay Z, wondering whether the rapper “is arguably crossing the line from husband to pimp by exploiting his wife as a sex object?"

Beyoncé and Jay Z have long maintained a close relationship with the Obamas. They, along with daughter Blue Ivy, were guests at Michelle Obama’s 50th birthday party, and Beyoncé performed at Obama’s second inauguration. This close relationship has made Beyoncé a target for conservatives in the past—in particular, Fox News host Bill O’Reilly has accused her of somehow encouraging teen pregnancies.

Huckabee, no stranger to controversial comments, claimed in 2014 that Democrats want women to think “they cannot control their libido or their reproductive system without the help of the government.”

But in picking a fight with Beyoncé, Huckabee may have crossed a line of sorts. The pop star is considered sacrosanct in many circles; the Saturday Night Live parody “The Beygency” pointed out the grave consequences for all those who criticize Queen B.

Spokesmen for Huckabee and for Beyoncé did not respond to requests for comment. However, when asked about the former Arkansas governor's comments on Wednesday, former President Jimmy Carter told TMZ that "he doesn't agree with much Mike Huckabee says [and] thinks President Obama is doing a good job."