You mean both chambers that are now in control by his party?

Also, a president doesn't have to declare war to engage in military conflict.

"For the United States, Article One, Section Eight of the Constitution says "Congress shall have power to ... declare War." However, that passage provides no specific format for what form legislation must have in order to be considered a "declaration of war" nor does the Constitution itself use this term. In the courts, the United States Court of Appeals for the First Circuit, in Doe v. Bush, said: "[T]he text of the October Resolution itself spells out justifications for a war and frames itself as an 'authorization' of such a war."[2] in effect saying an authorization suffices for declaration and what some may view as a formal congressional "Declaration of War" was not required by the Constitution. "

https://en.wikipedia.org/wiki/Declaration_of_war_by_the_Unit...

Valid points, indeed.

...unless they decide to just have Pentagon lawyers print up a lot of paper that says whatever they're doing falls under existing authorizations that consistently get renewed without debate.

Maybe they can go on a hunt for WMDs in the great white north???