http://ggould.blogspot.com/2007/11/i-came-to-talk-about-draft.html
There's nothing I can add to this that your commenters haven't already. Except that having a draft wouldn't keep the military from having "an inordinate proportion of low-income young people": the rich and connected would still find ways to get their exemptions.
Indeed, some weeks ago, Time magazine did a
10 Questions fluff piece with the dullard Jenna Bush in which, on being asked why she and her sister aren't serving in their daddy's war, she replied, "if people really thought about it, they would know it's not even a practical question." (Fortunately, a veteran's wife had the presence to ask in a letter the next week, "Ms. Bush, for whom is war
practical?")