If only this latest bit of insanity could be the straw that broke Moscow Mitch's back (or his power). If only...but I'm not holding my breath.
Congress must give consent to an open declaration of war and the last time that happened was WWII. But that doesn't mean that a POTUS can't engage the US in military action. There was never a declaration of war for Viet Nam and we had active troops fighting there for 10 years. That's why technically it's called the Viet Nam 'Conflict'. Same for Korea, it was a 'police action' not a war.
Scrotus can do will do a shit-tonne of damage without a declaration of war.
A War Powers Resolution (WPR) isn't a fait accompli. It has to pass the House and the Senate by simple majority. But a POTUS can veto it, just like any other law. Nixon did this to a WPR during Viet Nam in 1973. It takes a 2/3 majority vote in the House AND the Senate to override a presidential veto (which Congress did in 1973). In trying to get a WPR through the Senate, once again we're faced with Moscow Mitch and his henchmen/women.
Here's the Senate breakdown:
Majority Party: Republican (53 seats)
Minority Party: 45 Democrat & 2 Independent (47 seats)
(Independents both caucus with the Democrats)
It would take only 51 votes to pass a WPR so only 4 need to 'cross the aisle. But it would take 67 votes to overturn a veto. That's 20 crossing the aisle and the same number it would take to remove him from office. Unless there's a wholesale mutiny against Moscow Mitch, it's not going to happen.