the people would never win because they'd be fighting the American empire's forces
I think the US has been great at spreading the "we are so invincibly powerful" narrative, but, how would that actually work? Do you see the US military carpet-bombing their own cities? A nuke here and there?
Soldiers, in the end, are people. No matter how MAGA they can be, I bet most would think twice about bombing their own country and countrymen.