Don't mess with Alec Baldwin when it comes to the "Rust" case ... a Donald Trump look-alike just learned that lesson the hard way.

Baldwin was loading luggage into the back of his SUV in NYC when the Trump impersonator walked up to him on the street and started needling him about everything from the 2024 presidential election to his criminal case.

Check out video posted Monday to X, which shows The Donald doppelgänger -- known as Jason Scoop -- throwing zingers at Alec, who tries to ignore the dude while dealing with his bags.

The annoying troll doesn't let up for a moment and you can see Alec getting more and more pissed.

At one point, Scoop rubs Alec's nose in Kamala Harris' loss to Trump in the election. Of course, the famous actor voted for Kamala and did his own mocking impressions of Trump on "Saturday Night Live."

Then Scoop has the audacity to bring up the "Rust" case in which Baldwin was acquitted of manslaughter at trial after fatally shooting cinematographer Halyna Hutchins on the New Mexico set of the movie.

Scoop talks about Baldwin not wanting a pardon for "murdering that woman in cold blood," going so far as to say Hutchins is "looking down on me right now" and thanking Scoop for confronting Baldwin over her death.

That pushed Alec over the edge and, in classic Baldwin fashion, he got right up in Scoop's face.