Tony Snow: Supremos Don't Decide Constitutionality

Well, down to one branch.

Me: But isn’t it the Supreme Court that’s supposed to decide whether laws are unconstitutional or not?

Tony: No, as a matter of fact the president has an obligation to preserve, protect, and defend the Constitution of the United States. That is an obligation that presidents have enacted through signing statements going back to Jefferson. So, while the Supreme Court can be an arbiter of the Constitution, the fact is the President is the one, the only person who, by the Constitution, is given the responsibility to preserve, protect, and defend that document, so it is perfectly consistent with presidential authority under the Constitution itself.