The 59-year-old actor said that he simply had to pick up a few things to get the character right, reported The Independent.
Talking to Stephen Colbert on "The Late Show", Baldwin said, "It's totally a caricature. You just pick a few things. Like, I'm sitting in the room and I'm going, 'Left eyebrow up, right eyebrow down, shove your face like you're trying to suck the chrome off the fender of a car.'"
"It's kind of eerie. More than anything I've ever done, people come up to me and say something to me on the streets."
He added passers-by are "always thanking me for the Trump thing.