Supporting rioters that attack people over the perception of them being racist, white supremacists and the such is unironically fascist. Why would you support the attack of groups like the alt-Right when they have yet to result to political violence in mass numbers? To the everyday bystander, the use of political violence is both just intimidation and will ultimately make them think that the side condoning and using political violence are losing. Ultimately, they will paint the left as militant and then justify their use of retaliatory violence as law and order; the difference here being is that the populous will see it as self-defense.
The radical left is doing nothing to ironically causing the divide themselves. By alienating the support of the proletariat they so eagerly want to defend (as let's face it, the working class were a huge majority of Trump's votes), you are the cause of the growth of the alt-Right. You cannot fight a ideological cancer by suppression; it will always fester and grow. By logical debate, it is much easier to discredit the alt-Right, and while it won't change their opinions, it would prevent other people from joining them (such as conservatives, centrists, centre-left and generally anyone appalled by the current state of the Left).
Now, why do I argue that Antifa is being fascist themselves? By the definition of Fascism given by Dictionary.com and Merriam-Webster, this is the definition of it:
Firstly, by severe economic regimentation, this is ultimately referring to the third position in economical politics. This basically means that Fascists are against both communism and capitalism, as they want control of absolutely EVERYTHING in your life and hate those darn commie pinkos. As said, Antifa seem to be Anarcho-Syndicalists or Anarcho-Communists, but I'm pretty sure they're Syndicalists due to where the red is on the flags they carried during the #DisruptJ20 event. Syndicalism is an economic theory in the ownership of the means of production and distribution are given to labor unions. This is a key part; Syndicalism has been used in Fascist governance, such as Nationalist Spain's Falangist party under the ideals of National Syndicalism.
Here's a Wikipedia page (not perfect) describing it. The difference here is that they believe in using it to suit the needs of integral nationalism.
Secondly, they have already demonstrated that they want to forcibly suppress who they believe to be Fascists, "alt-Reich" or Neo-Nazis. That is a given; it was done under Anarchist Catalonia and their whole spiel of Anarcho-Syndicalism themselves.
And finally, in order for their "anarchy" to work, they would use their syndicates to rule over the people as seen with the aforementioned Anarchist Catalonia and even Anarchist Aragon. These trade unions, who often used armed militias, basically ruled with absolute power, similar to that of a military dictatorship. While they are not nationalists, the comparisons between them and actual Fascists are hugely comparable. To condone such violence is inherently undemocratic, and if you ever undergo any political violence, I don't have faith that the courts will give you a smack on the wrist.and let you go.
