Actually, they're not. Seeing that this is what passes for "conservative humor" nowadays, is anyone surprised that "The Half Hour News Hour" was an abject failure? You don't have to answer that.
Download 
Download CNN:
During a speech before the National Rifle Association convention Friday afternoon in Louisville, Kentucky, former Republican presidential candidate Mike Huckabee — who has endorsed presumptive GOP nominee John McCain — joked that an unexpected offstage noise was Democrat Barack Obama looking to avoid a gunman.
“That was Barack Obama, he just tripped off a chair, he's getting ready to speak,” said the former Arkansas governor, to audience laughter. “Somebody aimed a gun at him and he dove for the floor.”
How is this even remotely funny? I know the Huckster is quick on his feet, but how did he think of this "joke" so quickly? That's some serious improv skills right there.
UPDATE: Huckabee does the right thing and apologizes:
"During my speech at the N.R.A., a loud noise backstage, that sounded like a chair falling, distracted the crowd and interrupted my speech. I made an off hand remark that was in no way intended to offend or disparage Sen. Obama. I apologize that my comments were offensive. That was never my intention.”
