There are no white supremacists or Nazis that do not believe in expelling all non-whites from America.

I'd wager most people who identify as a Nazi or white supremacist do not want non-whites in their country. I'd also wager that most of those people are unwilling to achieve those goals by mass violence or killing Americans wholesale. I have nothing but conjecture, but I think there are vocal racists, white nationalist activists, and then there are white nationalist terrorists. I'd be willing to bet all three of those stereotypes were in Charlottesville, but only some of them are willing to go to violence to achieve it.

The only thing I have backing up my assumption is the fact that the USA doesn't have epidemic levels of racial violence. Without sourcing, there's possibly been an uptick in reportings (there are some problems with the data collection) but this is still a relatively tiny set of violence.

The reason I'm rambling on about this is to try and build some backing for my initial statement: belief and action are two different things. Believing that America was built for whites and going door-to-door with a gun to enact those beliefs are two very different circumstances. Many people believe many terrible things in the US, but few are going beyond the realm of words to enact those beliefs.

There's nothing wrong with writing a book, maintaining a forum, or planning rallies. Anything violent in nature is most definitely monitored by the authorities and is already against the law. You're advocating for restricting beliefs and not actions. That philosophy in action can be abused very easily.