Suburban populism, a revolt against Rovian polarization politics.

E.J. Dionne, Jr. writes in The Washington Post:

The basis for this new majority is very different from the one Democrats enjoyed between 1954 and 1994. The old majority depended heavily on representatives from the big cities of the North and rural areas in the South. The new majority, as [Rep. Rahm Emanuel of Illinois] has been preaching, was built on gains in suburban and exurban areas and a new brand called "suburban populism," which he defines as "a revolt against Rovian polarization politics." The Democrats are increasingly the party of the metropolitan areas, suburban as well as urban, especially outside the South.