It's amusing to watch, really. Just promising the world, anything that comes to mind.
Immigration: "Yeah, fuck the Mexicans! They'll pay for the wall! And everyone gets a free gardener and housekeeper, good for one year!"
Economy: "Everyone gets a job! Fuck it, you get your own company! And China PAYS US all the money we owe them!"
Military: "Pfft, you kidding? No one messes with us again: Skynet, starfighters, cyborgs, invisibility cloaks, doomsday device, Frodo's ring, hyperspace button, all that shit! USA! USA! USA!"
And they clap, and whistle, and cheer, like he means it. The dumb monkeys.