Dec. 7 was once a significant date on the American calendar. But sometime in the past 20 years it faded almost entirely out of view. Partly this was generational and partly it was historical, as the end of the Cold War drew a line under the era that began with the day of infamy. And partly it was a matter of indifference and neglect.

With that in mind, here's a forecast for tonight's result: Starting around the time the returns from Pennsylvania and Virginia are announced, 9/11 becomes another Dec. 7.

On...