Let us swing the door ajar and invite the elephant into the room. One big reason Barack Obama is locked in a tight race, rather than easily outdistancing his opponent, is because he is black. That factor is rarely discussed in polite political conversation. People tend to dance around it, talking instead about Obama's perceived inexperience, or his youth, or his perceived airs, or his liberal voting record. And racist sentiment rarely shows up in the polls, because a lot of people don't want to share their baser instincts with the pollsters; they'll save that instead for the privacy of...