Even if it did, I get the feeling that this is one of those questions that will never be definitively answered -- no matter how sophisticated the statistics. 4 or 8 years of an Obama White House would simply coincide with too many other events to prove that it was Obama's election that caused the change.
I'm unconvinced that the President (or anybody in the federal government) has the policy tools necessary to fundamentally alter what happens "on the ground" in schools around the country -- which is the only way, in my opinion, that we could expect dramatically different results. But I can't help but wonder if an Obama victory would have some sort of intangible effect on the outcomes of students. Beyond whatever policies he, Linda Darling-Hammond, and the rest of the team would establish, it's not implausible to envision an Obama presidency positively impacting the achievement of African-Americans in any of the following ways:
1.) African-American students gain a new role model. And trying to be like Obama results in higher test scores than does trying to be like Kobe, 50 cent, etc.
2.) The presence of an African-American in the White House reduces the amount of racism in America. The families of African-American students benefit -- through both lifted spirits and fattened wallets -- in ways that help their children do better in school.
3.) Members of all races and ethnicities reduce the amount that they stereotype and students and teachers expect more similar achievement from all students.
I could list more, but I think they start to overlap after a certain point. Whether you believe that these plausible would rely both on whether you think an Obama presidency would have any effect on how people perceive race and on what you think causes the achievement gap.
If you believe the gap exists because African-American students aim low, then idolizing the Editor of the Harvard Law Review could raise the achievement of many students. If you believe the gap exists because African-American families suffer from racial discrimination, then a more tolerant society could lead to a lower achievement gap. If you you believe the gap exists because the peers and teachers of African-American students expect less of them, then the sight of an African-American in the White House could plausibly raise these expectations and, therefore, raise achievement of these students.
Of course, this is all pure speculation. While it's a pretty sure bet that Obama will win the election, I really have no idea if or how the presence of an African-American in the White House will affect race relations in this country. I suppose one could construct a plausible scenario in which an Obama presidency leads to a resurgance of the Ku Klux Klan or some such nasty consequences. And I suspect that, regardless of what happens, we'll never be able to confirm those effects in a statistically rigorous way. But I still think it's something worth thinking about.