Read other letters about this article
It's not surprising they are trying to incite the assassination of Barack Obama. After all, the McCain/Palin campaign's speechwriters used lines from Westbrook Pegler in Sarah Palin's acceptance speech. Pegler was a Jew-baiting crackpot and a supporter of lynching who called for the assassination of Franklin Roosevelt and Robert Kennedy. So yes, they know exactly what they're doing.
This is eerily similar to what happened in Israel, when the right-wing Likkud party ginned up a campaign to smear Yitzhak Rabin (whom they couldn't beat at the polls) as a traitor, terrorist and even a Nazi camp guard. The smear didn't win for Likkud but then again, it wasn't meant to. What id DID succeed in doing was inciting a young ideologue named Ygal Amir into assassinating Rabin, which he did.
For more:
http://daltonator.net/durandal/blog/?p=160