We're heading into the home stretch in America's unusually lengthy (six months and nine days) primary election season. Some three-quarters of Americans have had a chance to vote for Democratic and Republican candidates for Congress, and state and local offices. Their choices tell us something about the results in November. But not everything, including which party will win the apparently close battle for a majority in the House of Representatives. The consensus of those who follow these elections most closely is that the Democrats will win. The most recent evidence comes from the ultra-narrow victory of Republican State Sen. Troy...