I never did get why the word "supremacists", when it seems to me it should be "supremists"
But anyway...there are no nazis, there is no KKK. Sure there are remnants, but there is no real threat and no real organized effort. Any claims otherwise is just silly nonsense.
There is a real threat in that people are being killed by followers of this ideology. It is true there may be no person giving direct orders to these individuals, but the principle of "leaderless resistance" has long been promoted by these types and that is certainly an organized effort.