I wouldn't be surprised that a strong portion of those fellas genuinely are in it for things other than racism (farming/rural/breadbasket issues are probably a good ways apart from metropolitan or information age issues). Problem is, they don't want to believe their "brushing shoulders" with the hatemongers who have already formed a sizable enough subgroup to become the "face" of this crowd (eg. the photo of that Capitol rioter with that antisemitic t-shirt in full view is most telling). Hence the shilling of conspiracy theories about Antifa plants out to "smear" the movement. Those making them are probably doubling down on a "no true scotsman" fallacy, seeing themselves as the right and proper conservatives/republicans who were essentially framed. So, to sum up, a mixture of card-carrying racists and those in desperate denial of the former walking beside them for their own nefarious reasons still makes for an ugly result that loops on itself. More directly and punitively dealing with the former bracket is a no-brainer. Those in the latter however probably will only come around if they have a jarring personal experience that not even the most reinforced tinfoil hat can explain away.