Nate Persily, Steve Ansolabehere, and Charles Stewart have posted this draft on SSRN. Here is the abstract:

The election of an African American as President of the United States has raised questions as to the continued relevance and even constitutionality of various provisions of the Voting Rights Act (VRA). Barack Obama’s apparent success among whites in 2008 has caused some to question the background conditions of racially polarized voting that are key to litigation under Section 2 of the VRA. His success in certain states, such as Virginia, has also raised doubts about the formula for coverage of jurisdictions under Section 5 of the VRA. This Article examines the data from the 2008 primary and general election to assess, in particular, the geographic patterns of racial differences in voting behavior. The data suggest that significant differences remain between whites and racial minorities and between jurisdictions that are covered and not covered by Section 5 of the VRA. These differences remain even when controlling for partisanship, ideology and a host of other politically relevant variables. The Article discusses the implications of President Obama’s election for legal conceptions of racially polarized voting and for decisions concerning which jurisdictions Section 5 ought to cover.

I read an earlier draft of this important piece. Highly recommended.