After Benazir

A reader writes:

I was talking to an African-American friend last week and they mentioned their mother was seriously frightened for Obama that "something will happen to him if he is nominated" i.e. he will be assassinated. Is this a generational concern or more widespread? Have you picked up on any such concern?

I hear it all over the place - and it's a common assumption among many African-Americans. I hope his security is getting tighter.