As a general rule, you should avoid throwing around words that you can’t define in a coherent fashion. For example, you shouldn’t call Ann Coulter a fascist unless you actually know what “fascist” means. It’s not enough to have a coherent definition, though. Your definition might be completely wrong.
One way to attack people you don’t like is to do some linguistic sleight of hand to justify name-calling. If I define “fascist” as “a person whose political views are to the right of Bernie Sanders,” then I can call just about anyone a fascist, if I want to. The problem is that my definition of fascism would be entirely wrong. Fascism, in fact, refers to authoritarian nationalism. By using the word in a way that is inconsistent with its actual definition, I obscure the truth and weaken the force of the word.
This is the problem that progressives have, nowadays. They just can’t stop themselves from referring to everyone on the right as Nazis, fascists, racists, white supremacists, etc., even though those terms aren’t at all descriptive of mainstream conservative views. They’re not even representative of “fringe” conservative views (like those of Milo Yiannopoulos or Ann Coulter).
Imagine the situation reversed. Suppose right-leaning young people deplatformed anyone advocating for single-payer healthcare on the grounds that it’s a Stalinist idea. That would be ridiculous. Even if single-payer healthcare is a bad idea, it’s not Stalinist.
Highly charged words like “Stalinist” and “Nazi” shouldn’t just be tossed around like they don’t mean anything. They have meanings, and if you use the words in ways that are inconsistent with the meanings, then you’re contributing to the polarization of political discourse in this country. You’re also creating more room for authoritarianism by inciting panic at all the so-called “fascism,” “white supremacy,” etc. in our country.