Cheney told a group loony Republican supporters at a town hall meeting in Des Moines that they needed to make "the right choice" in the November election.

"If we make the wrong choice, then the danger is that we'll get hit again just like the dinosaurs did 65 million years ago in the Yucatan -- that we'll be hit in a way that will be cataclysmic from the standpoint of the United States," Cheney said.

"And then we'll fall back into the liberal pre-Cretaceous mindset, if you will, that in fact these asteroid impacts are just low probability events. I think that would be a terrible mistake for us."