Reason reports Me Dees money machine, the the Southern Poverty Law Center, is producing numbers purported to be of “extremists.”
Dees has gotten very, very rich with his dodge, but even his resources would be strained to actually do what he says he is doing. The only people who lap that stuff up are the media, which evidently pay handsomely for such data. Otherwise, I cannot see a reason to bother with what amounts to “creative fiction.”
Actually, I strongly suspect the number of actual hate groups is largely confined to the political left, since the various and sundry “segragationist” groups of sixty years ago have disappeared and nothing has taken their place. Or if something has it is so deeply buried it has not come to my attention.
Since “Old people have big ears,” I doubt that such a group would become active without attracting attention.