Joe Raedle / Getty Images

Donald Trump might have just run afoul of the one thing more stubborn than himself: the NCAA.

During a campaign stop at the University of Iowa last night, Trump invited several members of the school’s football and wrestling teams up on stage with him in a show of masculine bravado. It was a shrewd political move in Iowa, a state that takes football and wrestling very seriously, but it may have violated the NCAA’s bylaws. 

According to the NCAA’s guidelines on advertising and promotional activities, endorsement of a political candidate or party is a big no-no. As is endorsing public personalities “whose personas/images are inappropriate for NCAA audiences (e.g., those who promote hatred, misogyny or discrimination.)”

The Washington Post reports that members of the team met privately with Trump before the public event. It’s unclear whether the athletes were simply in attendance and ushered to the stage once spotted by Trump—who has a tendency to improvise—or if they had agreed beforehand to make an appearance on stage.