The War Powers Resolution is a tricky animal. There's a good argument that not all of it is constitutional, but it does represent a decent starting point for any discussion of the President's discretionary war powers.
A President probably has the authority to launch a one-off strike as we are currently considering with Syria, but this is really not the situation contemplated by the War Powers Resolution. This is not an emergency. There is ample time to consult with the Congress and obtain proper authority for the use of military force.
This is yet another example of Obama's disregard for the democratic process, which if allowed to proceed, would probably nix an attack.
(P.S. - I agree with Ted Cruz.)