I really am not ready to hear that Tom Cotton may be in this group. I thought he was a "good conservative" as well.
Do you also remember back during the campaign that he was one of the attendees at some secret getaway (was it in Georgia, can’t remember) where the discussion topic was developing Take Down Trump strategies? I vaguely recall hearing about this “retreat”.
Tom Cotton served under McMaster so he has a personal relationship with him. I think this is why Cotton was receptive.