Article from the National Journal.
In the map and chart below, National Journal projects the percentage of the white vote that President Obama will need to carry an individual state in 2012. The baseline simulation makes two key assumptions. First, that Obama captures as much of the minority vote in that state as he did in 2008. Second, that the minority population grows over the next two years at the same rate it has since 2000 and produces a commensurate increase in the minority share of the electorate. The chart shows where the growing minority presence will allow Obama to win states even if he loses support among whites—and where he will need to increase his support from whites to prevail.
If President Obama cannot maintain his 2008 level of support among nonwhite voters, his electoral math looks tougher. In the reduced-support scenario, National Journal cut Obama’s nonwhite support by a tenth in each state he carried in 2008. The percentage of the white vote Obama would need to carry the state then rises compared to our baseline, especially in states with a significant nonwhite population. This scenario shows the president needing to maintain or increase his support among white voters from 2008 levels to hold onto some electoral-vote-rich battleground states, including Florida and North Carolina. But because Obama performed so well among whites in many states he won, he has room to fall and still carry these places a second time.