It seems to me that CPAC does some cosmetic purging every year, but they really can’t keep the racists out because the conference wouldn’t have many attendees if they were meticulous about purging racists. Even Donald Trump used his time to complain that we don’t have more European immigration.
So, they can keep Pam Gellar kind-of sort-of out, and they can ban any official role for the John Birch Society and they can cherry-pick a couple of notable white power folks to exclude, but there’s a reason all those folks are attracted like flies to CPAC. The conservative movement is a racist movement, and has been since forever.