What is the thread you claim links these things?
That's not to say that there isn't some truth to those sentiments, but I'm much more interested in evidence or at least a stronger theory behind the alleged correlations. As written, the original comment at face value is nothing more than one person's opinion based on, who knows what?
Rather, I think it sets up the potential to be susceptible to them. TRP, for example, does a great job of channeling the (understandable) anxiety and frustration of unloved young men into negativity and hate.
The other political groups being implicitly white is a mere correlation (not causality) in the same vein as Hitler drank water, Trump drinks water, therefore we have proven Trump is Hitler.