Nativism and anti-immigrant positions do belong to Nazis and white supremacists.
You might wish that but history says otherwise. A dispute over open/closed borders isn’t cause for violence.
https://en.wikipedia.org/wiki/Nativism_(politics)
“Nativism is the political policy of promoting the interests of native inhabitants against those of immigrants.”
https://en.wikipedia.org/wiki/Nationalism
“Nationalism is a political, social and economic system characterized by the promotion of the interests of a particular nation, especially with the aim of gaining and maintaining sovereignty over the homeland.”
https://en.wikipedia.org/wiki/Nazism
“Nazism subscribed to theories of racial hierarchy and Social Darwinism, identifying the Germans as a part of what the Nazis regarded as an Aryan or Nordic master race. It aimed to overcome social divisions and create a German homogeneous society based on racial purity which represented a people’s community.”
So yeah, anti-immigrant (that is non-native) positions do belong to Nazis and white supremacists. Arguments over open or closed borders are a singular aspect in a larger argument. There are more layers than just arguing over border security (like how to secure them, and against whom they should be secured). To say “A dispute over open/closed borders isn’t cause for violence” mischaracterizes the argument.