Barbara Boxer said yesterday that Bush should read the Constitution, because he is missing a key point -- Congress is there as a check against presidential power. Congress has the power to stop the president when the president tries to exceed his authority; they not only have the power, they have the obligation. So while he might be the "decider", he is one by permission only, and that role can be taken away from him by vote of Congress at any time.
I would like to see them make it nearly impossible for a President to command an attack against another nation without having to declare war. This is how more recent Presidents have skirted the issue, by creating "police actions" (Vietnam), to "anti-terrorist activities" (Iraq), wars in all but name. If we are going to send soldiers to fight -- it's a war. If we bomb from air or sea, it's a war. Call it what it is, and go through proper channels with the proper checks and balances set in place.
Make it a big and scary thing, fraught with political risk, to have to ask for, and get permission for the exercise of military power. Because it is a big, scary thing for a country to do, and it should not be taken lightly.