Any attempt at civility or discussion with a fascist is doomed to fail. Regardless of what they claim, fascists aren't interested in any form of debate, compromise, or exchange of ideas. Their only goal is to give their toxic ideology an appearance of legitimacy.
We are, by our very nature, pure anathema to the fascist. We espouse racial and economic equality which makes us, to the fascist, degenerate scum. He sees us as corrupting his proud heritage and willfully disrupting what he views as the natural order. We are vermin to the fascist, fit only to be exterminated.
You must remember that genocide is one of the central tenets of fascism, and whether they admit it publicly or not, something all fascists believe is necessary and just. They are well aware of what society will allow and will craft their statements carefully so as not to be immediately rebuked. They frequently cloak themselves in democratic ideals, like freedom of expression and right to assembly, while simultaneously working to destroy them.
Their only purpose in debating you is to make their toxic beliefs easier for the masses to swallow. If you engage a fascist in civil discourse, then they have already won.