On the last day of its 2010-11 term, the U.S. Supreme Court struck down a critical part of an Arizona law that awarded eligible candidates public funds to run their campaigns for state office, effectively killing the state’s public-financing program. To many, this news is a surprise: Public financing has historically been praised by federal courts for furthering constitutionally cherished values of equality, free speech and political participation. Indeed, in Buckley v. Valeo, a famous 1976 opinion, the Supreme Court stated explicitly that such programs “facilitate and enlarge public discussion and participation in the electoral process, goals vital to a self-governing people.”

So why, you may ask, did a narrow majority of the current Court, led by Chief Justice John Roberts Jr., disrupt Arizona’s long-standing and widely popular program? The answer, unfortunately, cannot be found in First Amendment law or in the facts of the Arizona case.