Can state officials demand to know what organizations you join and what charities you support? Or do people have the freedom to associate with whomever they please without being tracked by the government?

On Monday, the Supreme Court will hear two groups’ challenges to California’s demand for their donor lists. About 10 years ago, the state began mandating such data from all nonprofit organizations that ask Californians for donations. New York and New Jersey later followed suit. Their effort to pierce private association threatens the entire nonprofit community and the First Amendment.