Nazism - Don't be this guy

The literal genocide done by the Commies is just as bad-if not worse-then the literal genocide done by the Nazis. You celebrate that genocide or pretend it never happened. You are literally the left wing version of a Nazi, of course you are just as bad as they are.

…commies attack more than just fascists. They have ethnic group targets of their own (especially Ukrainians), internal political dissidents, Jews (especially the USSR when under Stalin; they used the term "anti-Zionism" to obscure the true nature of the policies they were enacting), intellectuals (thanks, Pol Pot), and the very proletariat they claimed to be out to protect.

Looking at more broad, more modern examples, you have Antifa, who are composed mostly of far-leftists (including many communists) who target "fascists" using the broadest definition of the term in human history.