Baldwin has Trump's mannerisms down pat.
The skit was not overtly funny, but it pokes fun a Trump's lack of intelligence.
I'm reminded way back when SNL used to parody George W Bush both before he was elected and after. I remember before he was elected, they had this debate set up in the skit and the moderator of the debate was asking questions to Will Ferrel about the Balkans and throwing all the Balkan names and places at him and Ferrel did an amazing job just with his eyes and a very slight facial change that conveyed to the viewer both panic and that Bush / Ferrel didn't have a clue of what he was being asked. Ferrel's response was "Ok, I think that we have to support "the first guy" and try to get rid of "the second guy".
It was very nuanced comedy.
Baldwin's portrayal of Trump reminds me of that a lot.
The point being that Trump is in way over his head now.