A reader writes:

What McCain and Palin are doing now makes the Clinton campaign look tame. It occurs to me that they are "legitimizing" putting Obama's life in danger by pushing this nonsense. The first potential Black President is always going to have that problem, hell Bush had people trying to take him out, I'm sure, but this is really raising the threat level.

Saying your opponent is unfit is one thing, suggesting that he is a evil, a friend of terrorists and a danger to the United States is something else entirely.