The most successful genocide is when you convince your victims to do away with themselves. Of course the American government isn't protecting people from disenrollment: fewer Indians means fewer expenses. But government shouldn't be let off the hook just because one tribe doesn't want its members anymore. The government still owes those people. It just doesn't care. It never has cared.
The only good Indian is a dead Indian.
Someone should really lay genocide charges in international court. The evidence is pretty brutal.