It simply is not the case that a court can properly be described as activist just because it enforces the Constitution’s structural limits on federal power. In this context it is not altogether helpful to focus the discussion of whether the Court’s acting properly on the contours of the word “activist” or “activism.” We have to remember that, for the Supreme Court, not acting to invalidate an unconstitutional law is every bit as bad, is every bit as repugnant to the rule of law and the Constitution, as it is for the Court to act to invalidate a law that is entirely justified on a constitutional basis. Both represent and both are a product of a betrayal of the Supreme Court’s duty to decide cases according to the laws and to the Constitution of the United States of America. When the Supreme Court acts to enforce the Constitution’s limits on federal power, as I expect it may do in the Affordable Care Act case, it does so pursuant to specific textual provisions of the Constitution. Enforcing the law in this undeniably legitimate manner is not activist, rather it is an essential function of the judiciary in preserving the liberties guaranteed by our Constitution.