- I disagree with you.
Banning literal Nazism is not a "gateway" to authoritarianism. Nazism has absolutely no place in society.
What you're talking about is covered in the Tolerance Paradox.
"But we should claim the right to suppress them [intolerant ideologies] if necessary even by force; for it may easily turn out that they are not prepared to meet us on the level of rational argument, but begin by denouncing all argument; they may forbid their followers to listen to rational argument, because it is deceptive, and teach them to answer arguments by the use of their fists or pistols." - Karl Popper, The Open Society and Its Enemies