GW Bush, Obama, and Biden all used a specific interpretation of a law called "2001 Authorization for Use of Military Force" to commit strikes on other countries without congressional approval, which is exactly the precedent Trump is trying to use here. Congress in truth likes this so they can do things like this and pretend to be upset about war instead of having to defend their yes votes for it, as many of their donors would require of them. If they really wanted to do something about this it boggles my mind that in the 25 years since that law, they've never rallied specifically around repealing or re-interpreting it and have scarcely even called attention to it.