The "rightness or wrongness" of this war has been discussed here ad nauseum and I won't do it again. The Constitutionality of the "war" however is clear. There is no Constitutional req. for a President to get permission from Congress to send troops into battle. This is what drove the War Powers Act to be passed, vetoed and overridden. Many people, I mean lawyers, think that the War Powers Act itself is un-Constitutional but no President has seen fit to send it to the Supreme Court and they all have ignored it at one time or another since it was passed. Personally I would like to see it sent before the court because not only would they have to rule on it, it would probably force them to define war which would more clearly define what the President has to do to send troops into battle. Before anyone gets too excited over that however, thinking it will limit actions such as Iraq without a formal declaration, I would suggest you read some federal and supreme court rulings that reference the executive branches ability to wage war. Both courts have been very generous in allowing the executive branch to wage war(s) and ensure national security without interference from the other two branches. Recent rulings wrt "illegal combatants" show the courts feelings on the matter.