This is a difficult question. Communism has led to countless unjust senseless deaths. Many people alive would be dead in a traditionally communist regime. Should we make communism objectionable as a political ideology? (note: I am not saying naziism should not be objectionable, just that we have an equally deadly ideology that has some acceptance)
Communism, expressed as the kind that killed all those people, is objectionable. I object to it, and it seems like a broad segment of the population agrees.
However, that just isn't the same as what I'm describing. There is nothing analytical about communism that poses an existential threat to me. Neo-Nazism, on other other hand, is a priori incompatible with my existence.
I do see this difference. However, in practice communism and faschism are pretty much two sides of the same coin. One has specific victims (though like communism, none stated, but there is always the out-group, I mean, you see Black African nazi sympathizers in Africa) communism also has an out-group: whether it be the owner-class or people who get in the way of their ideology.
Sure, there's plenty of violence in the world. I am opposed to most forms of it.
But no, there is no equivocation here. One of these things (Neo-Nazism) is fundamentally incompatible, even just on the linguistic level, with my existence. The other (Communism) is undesirable and even reprehensible, but doesn't threaten the mode of discourse itself.
Put another way: proposing tolerance towards analytically intolerant ideas amounts to an "disagreement" between a linguistic claim and a claim about the language itself. I wrote about the danger of viewing these as normal "disagreements" about a week ago[1].
These things are fraught with complication.