I agree with Dana that classism is "ugly" I just see little evidence that it prevents white people from getting jobs. Dana notes that "A person's class identity is often revealed by their accent, the particular high school or college they graduated from, and their ability to make appropriate cultural references."
Most of the class markers Dana identifies can be obscured or otherwise manipulated. Accents can be toned down, and no one needs to know what your parents did for a living or what kind of house you lived in. Appropriate cultural references and behavior can be learned. You can't change your skin color.
In general, I believe people place too much emphasis on a degree itself. The social connections you make in such a place are what people pay for, more than the education one receives. To the extent that people from more prestigious schools maintain a monopoly on certain high level jobs, it has more to do with economic factors than active discrimination against people of a certain class level (I could see an argument that there is no distinction). Still, extending opportunity to people based on class is better addressed by dealing with access to said institutions through class-based AA, not by encouraging hirers to make assumptions about class based on the fact that someone went to a public university.
Which brings me to another question: How would you implement a system of class-based AA in hiring? Should we start encouraging people to identify their class background on their resume? How would you verify that someone comes from that background without invading their privacy? Race and gender based AA is possible because of an easy and informal identification process, but how would you implement one based on class? Class-based affirmative action makes sense in college admissions because of the level of information given to colleges during the application process. It's just not the same when you apply for a job.
You can take the entire '08 class of any school and put them in suits and no interviewer would know what their class background is. But in only a few circumstances would you be able to hide their race or gender. These things are visible. We have a history of legal discrimination against people based on both factors, one which has led to a cultural legacy of assumptions made about ability based on such factors, which is why a corrective makes sense. Superficial class markers, by contrast, are arbitrary and based on perspective, and even in circumstances where white people are legally required to disclose class markers (say as in a prison term) they still have an easier time getting a job than a black person without them. Arbitrary class distinctions based on accents or what school you went to are simply not comparable to the cultural remnants of legal impediments that once existed preventing minorities and women from getting jobs.
--A. Serwer