Will the Obama Coalition last?

Nate Cohn argues that despite doubts, the coalition that elected Obama in 2008 not only held together in 2012, might survive for some time to come. This is based on a comprehensive analysis of the electoral released recently by the Census Bureau. The white share of the population continues to decline, and as long as that's the population that is the Republican Party's base, the future looks dim for the party. Whites right now are 73.7% of the population, but only 58% of 15-18 year olds.