“These rules and principles are not new,” declares the Supreme Court, in the introduction to its inaugural code of conduct, which it released on Monday. What, then, is the point of the code — particularly because, as many critics have noted, it lacks any mechanism to compel justices to follow it? The justices were already supposed to observe, in Chief Justice John G. Roberts Jr.’s words, “the highest standards” of ethics, yet recent revelations show some of them were not.