Alec Baldwin Teaches Boy Trump Impersonation ... And It's 'SO FANTASTIC!'

3/21/2017 4:04 PM PDT

Alec Baldwin's got his Donald Trump replacement lined up if 'SNL' ever needs one ... and he's just great, so great!!!

Alec teaches a young boy his hilarious impression of the prez. The kid -- a kid reporter, we think -- scored when he got Alec to demonstrate at the star's premiere of his new flick, "Boss Baby."

Watch and learn.