I'm not that much informed about the details of the US inner politic situation, @Simon - but what I know for sure is that almost (or all) European radical far-right (as well as far-left) movements/parties are sponsored from Moscow.
My guess is something similar might be well happening in the US. It doesn't matter whether you're left or right, black or white, or whatever - they just need to create some chaos/violence (real 'civil war' would be the best scenario for your enemies).