Someone will no doubt correct me if I'm wrong, but I suspect that most if not all of the inmates currently playing the tard card were convicted prior to the Supreme Court Ruling regarding the execution of those deemed to be Mentally retarded. As you say, they're playing the game just like they do with their claims the Lethal Injection is cruel and unusual punishment. I believe these cases will slowly be weeded out, and if adequate evaluation is carried out by prosecutors prior to deciding whether to seek the DP or not these cases should slowly dry up. The only problem is that these cases seem to take many years to be resolved.