That is only if this is called a war. It can be called a million other things that Republicans say are not the same thing as war. They've done it before, and the Dems know they will do it again. This will be a series of targeted strikes that are not retaliated against by Iran in any way that actually hurts Congress-people. Vietnam War wasn't even actually a war. Congress approved troop deployments one time, but that's about it.

Additionally, Republicans have the majority in both houses. The only reason the shutdowns have occurred is because they needed more than a simple majority to get the budget passed. Declaration of War does not have any documented rules for whether it is simple majority or 2/3 vote or whatever. In the past, a simple majority was assumed since the votes were never close enough for it to matter.