I read an interview by Haysbert - the guy who played Pres. Palmer and who still does the commercials - and he didn't want the President assassinated because of the possible influence, for some nut to try to kill our current President, Bush. He got very testy about it - it wasn't that he didn't want out, it was the way they were going to do it that bothered him.
Now some may not give him credit for being concerned about the assassination of a fictional President on TV, but I think I agree with him. It wouldn't take much for some nut to attempt to do it and then claim that he got the idea from a TV show!
Saddam tried to assassinate the first President Bush, so that was still art imitating life, not the other way around.