PugJesus wasn’t saying there would be no murders of minorities if Trump loses. They phrased things poorly, but what they meant was minorities are going to be thrown into concentration camps which is what the fascist nazis did.
Sarcasm implies you mean the opposite of what you said, generally:
‘Fascism is when there are murders’
Yes. That is not the sole thing about fascism, but murdering everyone not in your personal social group is kind of a big deal in fascism. You making this statement sarcastic does not reflect well on you or your ability to wield the English language. If you wanted it to come across the way you wanted it to come across, you should have said ‘Fascism is about when there are murders and nothing else’.
However, this would have revealed a deep misunderstanding of what your opponent was actually implying, and, ironically, strawmanning them.