One problem not addressed is the credence simply given to the new noun "alt-right".  It is a made-up name (like BRICS) and has no real meaning.
Does it come from the ctl-alt-delete computer command used to wipe out data and reset computers?
Or does it mean "alternative-right"?  Or "altered-right"? Or even "A Loony Troop- Right"?
I have heard people convinced of all these.  One thing is sure though, since Trump's election it appeals to right-wing white nationalists in the USA, (who are often racist in word and deed.)