I think there are two competing and perhaps overlapping issues here affecting medical schools:
1) Helping minorities to gain access to higher education.
2) Providing health care to underserved communities.
1:
Referendums like this always seem to pass. My guess is that this is because the American ideal of rugged individualism ("pulling yourself up by your bootstraps") is held so strongly by so many. As I've volunteered more and as I've reflected on my upbringing next to an Indian Reservation, I've begun to veer from this opinion myself. I would argue that at least two groups have had their bootstraps ripped away through varying degrees of oppression throughout American history: African-Americans and Native-Americans. Both groups had thier culture and history ripped from them. They were rounded up and coraled like livestock, their dignity was stolen, their self-worth was crushed. Black folk weren't allowed to read. Indians weren't taught to read. If noone in a family has read for generations, how does a child learn to read? Or to understand the importance of education? Or to even believe it's possible to improve one's lot in life? The cylce continues throughout the generations (reck1ess stated this case more eloquently and succinctly in his post above). AA is one small way to give these groups a hand up. If anyone deserves a hand up, it is these groups. I don't think it is enough and that it may not be the most efficient way to go about it. Emphasis at the primary and secondary levels would certainly be more effective, but probably doesn't happen because it is more costly and requires long-term vigilance.
2:
Bringing higher quality/access to healthcare to underserved communities is a goal I think most would agree with. If AA is the only way in which we've been able to summon the courage to address this problem, then it is better than nothing. The quotes from doctajay above show the negative impacts that doing nothing has had in CA and WA already. Again, I think AA does not go far enough. Can't we provide greater incentives to work in these communities? Tax-breaks, mortgage rates, substantial pay increase, guaranteed 40 hr work week, and other perks could get doctors to go to these communities. The military gives scholarships and stipends. Why not have a domestic medical service corps that does the same? I'm not sure what all the answers are, but AA is not the only piece of the puzzle. It doesn't make sense to get rid of AA, however, without replacing it with other measures to address real problems and discrepencies.
If the MCRI passes, it appears Michigan will be taking a big step back (since AA is one of the few steps forward that's been attempted) in both of these areas.