Whose in Charge?

Glenn Greenwald today in an excellent post on General bashing by the armchair warriors of the Bush cadre. In it he also says:

The weaker and more stigmatized Bush becomes, the greater could be the likelihood of some spiteful, bitter, strength-seeking military offensive. Few things seem more unstable and dangerous than an isolated, unpopular, bitter, failed, frustrated President, sitting in the White House recalling the glory days when war and military might caused him to feel so good and strong.

But...But...But, you might say, what about our Constitution?

Section 8
The Congress shall have Power To lay and collect Taxes,....

...snip...

To declare War, grant Letters of Marque and Reprisal, and make Rules concerning Captures on Land and Water;

Would some legal eagle please get to work and ascertain if the vote in the Fall of 2002 (see The Iraq War Vote, Revisited) which Bush used as a pretext to invade Iraq will give him the power to order a bombing of Iran? An invasion of Iran? Nuking Iran?