Here's an article by an anti-fascist who is neither an idiot, nor p.c., nor a Zionist in disguise (at least, I can't see it):

http://www.kersplebedeb.com/mystuff/books/fascism/fashantifash.php

It's worth reading, though it is published by "Anti-Racist Action Chicago", one of the most violent and Zionist of the anti-fascist groups. 

The real danger presented by the emerging fascist movements and organizations is that they might gain a mass following among potentially insurgent workers and declassed strata through an historic default of the left.

He thinks that if the American left has a 'default', the workers might be lured by the fascists' adoption of left-wing and ecological language. I said it's an intelligent piece, not that it has any relationship to reality.

To my mind, the main problem with the article is its attempts to categorize political movements, identify with one of them, and arbitrarily excoriate another. He admits that the left has much in common with fascism. Why support one against the other?

A better approach, rather than inventing categories which attempt to make some opinions, not just wrong, but beyond the pale, is to take each viewpoint at face value. If someone says they think it in their interests to oppose immigration, instead of shouting 'racist!', explain why you think they are mistaken. Ah, but then you are opening up the hypothetical possiblility that they might have a more convincing argument than you. That's what anti-fascism and Zionism have to avoid at all costs. That's why they are always disavowing people, calling on people to 'hold them accountable' for their opinions, and stating whom they will, and won't 'share a platform' with.