On Friday, Harvard University announced its plan to ban students from being in final clubs, fraternities or sororities while at the same time holding leadership positions in official campus organizations, such as the student newspaper or sports teams. The move came after months of heated discussion over the role of such clubs in the Harvard social scene and concerns about sexual assault and gender discrimination.

But at least some of the clubs are putting up a fight. And even in the absence of threatened lawsuits, the school...