First a nit to pick with Frank, then a general observation to correct some myths about the Law and the Courts.
Frank wrote:
I bet there are a lot of red-blooded, chest-thumping self-righteous Americans right here on this forum who loudly supported the officer in Iraq (I believe it was Iraq) who unlawfully obtained evidence from a prisoner believing that the potential evidence would help prevent an ambush of his troops.
Yes, it was Iraq. But...
And the big
"but" is that he was a soldier, in a declared hostile country, in armed conflict. That is sooo different than what the police are called to do. Or are you now implying that the Military and Law Enforcement are one and the same. I don't think you are. I think you didn't give your statement much thought, when you wrote it. Enough of the nit...
Long Path has it correct, but I would put it in its historical perspective.
Article III, section 2 of the Constitution reads in part:
"The judicial Power shall extend to all Cases, in Law and Equity, arising under this Constitution..."
The part that is interesting/telling here is, "The Judicial Power." What is that Judicial Power? That power includes what is known as Judicial Review. It is in judicial review, that the Court decides what is and is not constitutional. In the case of the SCOTUS, they are the final arbiters for determining what the Constitution actually says. This was decided early in our history by the case, Marbury v Madison.
In Marbury v. Madison the Court ruled that a section of the Judiciary Act of 1789 granted the Court the power to issue writs of mandamus. The Court ruled that this exceeded the authority allotted the Court under Article III of the Constitution and was therefore null and void. Chief Justice, John Marshall, understood that if the Supreme Court issued a writ of mandamus (i.e., an order to force Madison to deliver the commission), the Jefferson administration would ignore it, and thus significantly weaken the authority of the courts. On the other hand, if the Court denied the writ, it might well appear that the justices had acted out of fear, again weakening their position. This ruling established the precedence of Judicial Review and has never been struck down by any succeeding ruling by SCOTUS.
So while the Constitution does not specifically grant Judicial Review, it is implied in the Judicial Power and upheld and first utilized by Marbury v Madison.
Incidently, the term that a law that is unconstitutional is null and void, while first used by Justice Marshall, was later expanded and exemplified by Justice Story in his Commentaries on the Constitution. It was Justice Story that said that such a law was not only null and void, but that it was null and void from its very inception. The term is not within the Constitution itself.