When reading one of the endless stories about a just-released poll Thursday night, a pair of numbers struck my eye: 60 and 37. Those were the percentages of white voters supporting Mitt Romney and Barack Obama in the ABC/Washington Post tracking poll. Overall, the poll showed Romney leading Obama 50 to 47 percent. The reason those two numbers struck my eye is that they are identical to the percentages of white voters supporting Republicans and Democrats in elections for the House of Representatives in the 2010 exit poll. Overall, Republicans won the House popular vote by a margin of 52...