The Supreme Court will soon decide a case with potentially significant implications for regulating nonprofits, Americans for Prosperity Foundation v. Beccerra. In the upcoming case, two nonprofits have challenged the constitutionality of a California law that prohibits the organizations from soliciting charitable donations in the state unless they submit to the state a list of their major donors. Although there are political overtones clouding the case – worries about dark money, the optics of conservative organizations challenging a liberal state’s regulatory regime – the legal issue at play is one with decades of interesting constitutional history: what conditions can the state put on charitable solicitation?