A big challenge to the health reform law is its individual mandate provision, which will be argued when the law goes before the Supreme Court next week. The constitutional justification for the mandate is the Commerce Clause, which gives Congress the right to regulate commerce among states. Opponents of the law argue that the mandate regulates economic inactivity — not buying insurance — and the Commerce Clause regulates economic activity. The Sixth Circuit struck down that argument saying there is no such thing as “inactivity” in the health-care market because everyone participates. The precedents supporting the law haven’t changed, which means the Republican Justices would have to change the underlying constitutional law, which they have proved capable of doing.