Very simple, scared to death of the RACE CARD that even muzzled the Clintons effectively!!!
Do Ann Coulter and Mark Levin strike you as two people who are "scared to death" about anything, let alone someone playing the race card on them? And yet, both think that this birther business is nonsense, and each have said so publicly.
To me, that speaks volumes. To birthers, that just means that they're both "part of the conspiracy".