Andy, I’m in favor of sunset clauses for large areas of legislation, but let’s take just one example from the 2001 Patriot Act: Section 215 greatly expanded the right of the Feds to “sneak and peek”. That’s fine with me. I can see why this might well be justified in the circumstances of the war against Islamic extremism (or whatever it is that the administration now wants to call it – I completely agree with you on that point), but I can see absolutely no harm at all in subjecting these provisions to the extra scrutiny implied by a sunset clause.
And this is true more generally. You cite various parts of the Act (the roving wiretaps, for example) as if I disagree with them. I don’t, but I do think that the grant of such powers has to come with some additional safeguards. A sunset clause does not jeopardize the course of an individual investigation, but it will help increase the chances that (a) such investigations are not abused and (b) that the general derogation from the rights of the citizen that they inevitably involve will not be prolonged any longer than necessary.
I also find it difficult to agree with the implication you draw when you say, “when Congress passes a law it is presumptively valid.” Yes, that’s true enough, but it’s no less true for a law that is subject to a sunset clause. In a democracy all laws are subject to repeal one way or another. A sunset law is just, potentially, another form of repeal, so what’s the big deal?
And if making these arguments helps the ACLU, that doesn’t worry me too much. Sometimes the ACLU gets things right, very often it doesn’t, but it shouldn’t be used as a bogeyman to bring debate to a close.