Maybe for 90 days, then he needs approval by congress.
Do you see Nancy and Dirty Harry giving it to him?
YES. The President has been very wise to prevent international isolation on Iran, he is working closely with European leaders on that issue, and Europe tries to keep China and Russia "sort-of" in the boat. When it gets critical, the most likely scenario is that Russia and China will oppose military intervention, and that Europe and the US (= NATO) start to do something about Iran. Congress cannot ignore that. So, let´s hope that NATO stay united on that issue - there´s hope, the situation is different than Iraq.
We may not need 90 days to bring about regime change there... But if push comes to shove, they couldn't refuse, it's far more serious than Milosevich "Wag the Dog" was in 1999 and GOP Congress gave early approval to that debacle. Or else Dems can kiss their security credentials goodbye forever, particularly 2008.