But Trump does know who Duke is. Trump is on record at least twice on 2000 commenting on Duke’s joining the Reforrm Party. Trump specifically said Duke as a bigot, a racist, a member of the KKK, and was bad for the Reform Party.
Good, then what is the problem? We know what he thinks.
In this case, Trump is simply NOT going to get drawn into disowning people that support him - no different with Democrats.
If you want a guy that disowns supporters, you had one in 2008 - and how did that turn out?