If it is the Unite the Right rally where someone died, there were multiple groups there, and not everyone was/is a white supremacist. So I do not believe he should be associated with any of them, unless he has a prior history with a specific white supremacist group. And would make this unjustified. However, I think it looks like he was involved with a specific group.
@alanb I cannot read the article on this computer, but found another one. The article I read said he was involved with a group "Rise Above Movement", which does have white supremacist connections (tho I have not heard of it). However, they did not offer any actual evidence of him being associated with them. You mentioned from your article, that he had tape on his hands, but I am not sure what that means. If indeed involved with this group, then fuck him.
But if it is biased reporting, which it might be if the guy in fact was defending himself from the black man he was "beating on", then maybe it wasn't a supremacist rally and just a Trump/Right wing rally.
Either way, I think everyone involved in that rally, on both sides, needs to take a break from politicking.
Btw, this was the article I found. It is reporting on the firing, not the actual article that got him fired. So the details are more vague, I assume.
http://fortune.com/2018/07/06/northrop-grumman-charlottesville-protest/