What happened to Charlie Kirk is absolutely terrible and should be denounced.
But the guy believed strongly in free speech. He 100% supported people saying whatever they want, and he said whatever he wanted including a lot of super controversial takes. From what I know about Charlie Kirk, he seems like one of the last people on earth to say "you can't say that" because he literally lived every day saying basically whatever he wanted without boundaries, and allowing people to say to him whatever they wanted without boundaries. There's 1700+ youtube videos of him and the people he was debating saying some really spicy stuff to each other, only watched a couple to get some context of who this dude was.
Godwin's Law is a real thing. When people start arguing politics, regardless of Left or Right, there is a remarkable tendency for them to resort to a Nazi or Hitler analogy. It's laughable to think that only one side of the political spectrum resorts to reductio ad Hitlerum. I've heard both Left leaning and Right leaning people get frustrated and pull this card for literally decades, it was a thing long before MAGA and will continue happen probably for another hundred years or much longer.
The internet is already full of comparisons between Charlie Kirk and Horst Wessel by all sides. I'm not surprised at all, even though that's a very complicated comparison, and there are likely a lot of other assassinations throughout history that could be considered closer to what happened. I think this kind of speaks more about how our culture tends to have a really collective interest in the nazi period and second world war, as pretty much anyone even with the most basic understanding of history knows something about this period so it's an easy thing to debate, comes up all the time, and is used to build a case agains the other side, literally all the time, by all political sides.
On a related note, let's take a moment to laugh at the fact every workplace across the CAF has "that guy" who compares everything to the Second World War and thinks they are a genius for seeing what the others don't see, because they "know history" there's probably great meme potential here...