If you want to stop wars like this, then petition the real beasts.... the ones in DC. Get them to revoke the war powers act as Damo has suggested. THAT is how you solve the problem. Because you know the politicians aren't going to being declaring war (as they are supposed to) if they know they cannot fall back on the ole "bush tricked us" excuse. If they have to take responsibility for their actions instead of pawning it off, they will be less likely to initiate military aggression.
The problems of the war powers act does not mean that any effort for change must be aimed at it alone.
Efforts to change it have been unsuccessful and this is a better focus. Why should we beg the government to do what's right all the while enabling them by sending them fresh corpses.
This is something that can be done without having to rely on ANY politician much less a majority of them. We should discourage recruitment, abuse our children of the notion and generally engage civil disobedience.