It's no secret that higher education is too expensive in this country; private colleges are really expensive; Ivy League schools are ludicrously so. But the latest biennial report from The National Center for Public Policy and Higher Education should make us pause to consider what that might mean in the long term. Describing the report, the New York Times says, "The rising cost of college -- even before the recession -- threatens to put higher education out of reach for most Americans.

"If we go on this way for another 25 years, we won't have an affordable system of higher education," said Patrick M. Callan, president of the center, a nonpartisan organization that promotes access to higher education.

"When we come out of the recession," Mr. Callan added, "we're really going to be in jeopardy, because the educational gap between our work force and the rest of the world will make it very hard to be competitive. Already, we're one of the few countries where 25- to 34-year-olds are less educated than older workers."

Although college enrollment has continued to rise in recent years, Mr. Callan said, it is not clear how long that can continue.

According to the report, the net cost -- that is, a year's tuition, fees, room and board, minus financial aid -- at a four-year public university last year amounted to 28 percent of the median family income, while a four-year private university cost 76 percent of the median family income. 76 percent! And among families with incomes in the lowest 20%, even a public university would be 55% of median income for one year.

There are innumerable consequences to a less-educated American populace, many of which are addressed by the report's authors, including reduced international competitiveness and deteriorating standards across American industries. And for those of us who still harbor the quaint notion that being educated is good for its own sake, it's dispiriting to see it growing further out of reach for more people.

But as someone who attended an Ivy League school (full disclosure: I went tuition free, as my father works there) and, just recently, taught there, this latest report also confirms a disturbing trend that the upper echelons of American higher education both demonstrate and reinforce: a move toward a more permanent educated overclass and a less upwardly mobile underclass.

This has always been the case in America to a greater or lesser degree, but it has escalated in recent years with the uber-concentration of wealth and the increase in college costs. And, as the cartoon above implies, it's not just the costs directly related to education and basic needs. The upper-class environment pervasive at Ivy League and other private colleges makes it exceedingly expensive for students to participate in college life. My alma mater, Columbia, is in New York City, which made social life particularly expensive. But wherever you are, if everyone around you has lots of expendable cash, you'd better have some too if you want to tag along (and thereby make the connections that will be so important later on in your professional life).

I spent a year of my undergraduate education matriculated at Oxford University, where, despite free tuition (a few years ago it became I believe $1500-2000 a year), students to this day disproportionately come from Britain's upper classes. It's a place where tuxedos are required for certain university events, and admission is based largely on personal interviews between applicants and the professors who will teach them one-on-one - all of which puts at a disadvantage young applicants not trained in the manners and mannerisms of the upper class. (This is not to say there aren't innumerable people at Oxford working hard to make the system more inclusive...not to mention that Britain's mechanisms of financial aid tend to be more reliable than those in the U.S.)

But the economic discrepancies that increasingly make the upper echelons of American higher education unavailable to most people (not just costs once college begins, but the costs of test prep and private high schools where guidance counselors have personal relationships with Ivy League admissions officers, etc) is furthering more of a British-style class discrepancy between a small group of highly educated young people and everyone else.

I was stunned at the affluence of the vast majority of my students when I went back to teach at Columbia. (Perhaps it had gotten more exclusive in the few years since I'd graduated...more likely I was not as aware of it when I was a student myself.) A couple of times I attempted to teach a Barbara Ehrenreich essay on the social meaning of the expanding number of live-in domestic workers in the U.S., and many if not most of my students found her analysis to be a personal attack: they all had live-in maids at home.

This isn't a rebuke to my students, who were for the most part intelligent and lovely people. Rather, it speaks to my worry that those of us who have the privilege to attend great universities and who may go into powerful or influential jobs in business, politics, media, etc, are increasingly cut off from the vast majority of Americans - and they from the opportunities available to us. This isn't a revelatory observation, of course - it's just another iteration of John Edwards' two Americas. But it's another element of why it's so important that Barack Obama follow through on his pledge to make higher education more affordable.