So here I am having these feelings of general support regarding the Libya action, with the feeling of dread that the (again understandable) hesitation may have created all kinds of problems. Not to mention the practical limits of engaging in yet another conflict. And yet one might possibly (but not necessarily) be persuaded to put these aside if the moral cause is, for lack of a better word, just.
What I've been struggling with is the lack of congressional authorization for the action. I understand the Senate passed a resolution calling for the UN to impose a no fly zone. But it's not quite the same as congressional authorization for implementing the resolution, if for no better reason than it doesn't carry the force of law. A terrific take on all this is in the NYT here. (Found via Steve Benen). I also know that presidents since Truman have been doing this (and many presidents have done so). That doesn't necessarily make it proper or constitutional either. (If you're interested, you can see the President's letter to Congress here.)
I suspect my feelings have much to do with the plain text of the Constitution, rather than any extended legal analysis or case law. I have a bar license, and appreciate the extent that the law is governed by extensive judicial case law, precedents, and legal analytics that operate to interpret often vague and inconsistent legislation. But this is different - this is the source law of the country, and the plain text matters - especially when it is, relatively speaking, clear.
Article 1, Section 8 says that Congress shall have the power "to declare War, grant Letters of Marque and Reprisal, and make Rules concerning Captures on Land and Water;"
Article 2, Section 2 says "The President shall be Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States;"
Congress has the power to declare War. The president is in charge of the military. These things square with each other in a system of separated powers. You can debate the scope of this all you want. But the Founders put the Congressional power to declare war there for a reason - it's not like they didn't "mean it". If you think about it, it makes perfect sense. The colonies fought a long war to throw off the yoke of a militant executive - King George the III! In fact, they abhorred central government so much that they created the Articles of Confederation before finally acceding to a more robustly centralized Constitution. But they still understood the risk of an executive assuming sole control of military operations.
Ultimately, this is why I have an issue with the way in which the operation in Libya was initiated, putting aside the War Powers Act (which itself is a whole other issue). Even George W. Bush got both the UN and Congress to authorize Iraq. Nuts, right?