The Volokh Conspiracy notes Justice Breyer’s aspirational nod to the last, best limiting principle in constitutional law:
And, of course, the greatest limiting principle of all, which not too many accept, so I’m not going to emphasize that, is the limiting principle derived from the fact that members of Congress are elected from States and that 95 percent of the law of the United States is State law.
As much as I’m willing to grasp at anything that might help the government sustain the mandate, I hope it’s obvious to everyone that while the democratic process is itself a limit on federal power, it’s not one that can be relied upon to restrain government action. The Constitution precommits us to certain values, with the knowledge and expectation that we might, one day, try to transgress beyond them. In such cases, the Constitution is there to limit the people’s transgressions against themselves, and snap them back into line.
The very essence of the Court’s countermajoritarian role is that elections alone are inadequate safeguards on popular liberty. If this is something we as liberals accept in social causes — when we try to invalidate validly-enacted, but nonetheless noxious bans on gay marriage — we can’t ignore it when it hurts us. That’s the conservative approach, so plainly on display on Erick Erickson’s site (judicial activism is fine when they do it, you see!). But we should be above that.