Although exit polls seem to indicate that Republican Bob Corker will keep the Tennessee Senate seat in Republican hands tonight, U.S. News columnist Michael Barone says that the networks' hesitancy to call that race highlights some of the problems with exit polling. Speaking on Fox News television, Barone said that people at the decision desk there believe there's at least a 6-point error margin in the sampling data of the exit polls. He also noted that, going back to 1992, exit polls tend to overstate the Democratic percentage and that half of all Americans on their way out of the voting booth refuse to respond to exit pollsters.