Intensity matters in politics and, at times, is more important than approval. It may be, and the ratings certainly suggested this was the case, that the television viewing public preferred Jay Leno to David Letterman when choosing which late-night talk show to watch. From a political standpoint, however, it would do a candidate for elective office little good at the polls to announce he was a "Leno person" or to denounce Letterman. Preference in late-night talk show hosts is simply not an issue on which people vote. On the other hand there are issues which, while they matter little to...