Here is the judges argument for why it’s not free speech among other arguments for the rulings they made. Free speech starts on 38.

https://storage.courtlistener.com/recap/gov.uscourts.nyed.459733/gov.uscourts.nyed.459733.54.0_1.pdf

Essentially they say he is not being charged for the words he wrote, he is being charged because the words he wrote were in the purpose of a crime to defraud someone. 

My gut says this case comes down to their intent. If he was actually trying to get people to think they could vote when they couldn’t and so trick them out of it, then I think he could be guilty. If his intent was, “this is silly”, then I think he wouldn’t be guilty. Which one of those is the case is a fact question. And Juries determine the facts of the case. In this case the jury heard his claim that it was satire and they didn’t believe him.

It’s like if I use words to trick a grandma into sending me money because I pretend to be her grandson in distress. I used words, words are free speech, but the charge isn’t that I said certain forbidden words, or topics, it’s that I defrauded a grandma. 

With more reflection on the original video I will say there is a lot of framing, assuming the framing is accurate it feels like a clear over reach and abuse. But if the framing is false it’s similar to the use of RICO. Which is a little shady, but that might be a better comparison in the US and can be abused.

Just my random opinion.