The multiple posters that were banned last week were not banned for using racially derrogatory language. AOL might pull threads or delete posts, but banning people from their service due to their political views would be another matter.
Aol has banned service to some people for any number of reasons and not just on the discussion boards.
Besides, you have to pay to join aol where as the discussion board called Free Republic is free.
Further, FR is more of a discussion board than a ISP.