At this point, I would try contacting ARIN or ICANN directly, showing them that their standard registrar model isn't working out (including evidence of any blatant policy violations that registrars have done), and ask if there is a special option to be hosted directly by them, or to provide a registrar that's contractually required by them to host anything.
The ability of registrars to collectively refuse to provide service because of PR reasons, effectively excluding someone from participating in the DNS without needing a court order, seems like a major gap in the ICANN policy. Did they really not address this in all the decades they've been operating? I'd double-check with them.