I'll comment. Check his sign up date.
What about it? He's been here over 3/4 of a year. It'd be one thing if he just signed up yesterday, but he's been here long enough that he probably would have been banned by now if he was a troublemaker. Therefore his date is not an argument for or against any particular position.
On top of which, he's absolutely right that an AOF is not a DOW. The President routinely talks about the Iraq war as having been his decision (most recently in his Oval Office address to the nation a couple of weeks ago). That would not have been the case if Congress had passed an actual declaration of war. We'd have been at war from the moment the declaration was issued, and it would not have been the President's choice at all at that point, except when he actually signed the thing.