The "white supremacist" label was attached by those who wanted to suppress the publication of the book, including government agencies, who wanted to suppress the book. I assume that if White Supremacists heavily promote the Constitution, it, too, will become "racist."
It is just a fictional novel, no different than dozens of others depicting resistance to an oppresive, corrupt government promoted by the Soros/Obama/Van Jones radical/progressive types.
There was an almost successful attempt to suppress the book, to threaten any publisher which would reprint it.
Fortunately, there are PDF copies available for free downloading on the web.
You got that right. This tactic has been being used for decades and is ever increasing in scope. Look at how the American flag is currently being treated in many circles. How about our founding fathers? How about American history up until about 1965? And a list a mile long. People are naive if they think race isn't and won't be used to destroy this whole nation no matter how 'non-racist' you are. Racist = white.