The analogy to the SA/SS is always the first resort since it’s the one most people are familiar with.
But the real analogy is to the Communist street gangs of the Rote Front in Germany and going back further to the evolution of the secret police in the Soviet Union who were simply the Bolshevik street fighters.
Translation: we have seen this movie before and we should understand what is happening not just in terms of similar history on the Right, but on the Left, which is what is being played out in front of us....again.
Many of which eventually switched sides to the SA.