According to the most recent report on population data in the military (for fiscal year 2004), African-Americans make up 15 percent of the military's ranks—very nearly the same as the 14 percent that they constitute of civilians aged 18 to 24. Hispanics make up just 13 percent of the armed forces—less than the 18 percent that they constitute of the civilian cohort.

Nearly all enlisted members of the armed forces—99 percent—have high-school diplomas or general equivalency degrees. Just 80 percent of all 18-to-24-year-olds do. (For what it's worth, 96 percent of officers have college degrees—38 percent advanced degrees.)

Aptitude scores are a bit tougher to compare, and the most recent report doesn't make the comparisons. But an earlier edition did, and suggested that, on average, members of the armed forces are "smarter" than civilians of draft age. A draft—a truly equitable draft—would draw in more upper-class, highly educated young men and women, but it would probably draw in even more (as that captain put it) "riff-raff."