Obama was able to build his electoral vote majority thanks to big Democratic majorities from core constituencies concentrated in these states, which gave him 207 electoral votes.
But the concentration of blacks, Hispanics and gentry liberals means there are fewer Democratic votes in the suburbs, the countryside and the geographic heartland. The Obama campaign strategy concentrated on turning out core voters. That left House Democrats short of the votes they needed elsewhere.
In state legislative races, Democrats also rebounded from 2010, but fell far short of the losses they sustained then. They went into the 2010 election with 53 percent of state senators across the country and 56 percent of state lower House members. (Nebraska elects its one legislative chamber on a nonpartisan basis.)
Democrats came out of the 2012 election with only 46 percent of state senators and 48 percent of state lower House seats.
In that time, they gained seats in both chambers in only three states: New Jersey (one seat in each body), Illinois and California.
Democrats still hold most legislative seats in the Northeast. But Republicans now have more state legislators in the Midwest, West and South.
The changes in the South have been especially striking. Democrats went into the 2010 election with 51 percent of state senators and lower House members in the South. They came out of the 2012 election with 38 percent of state senators and 40 percent of lower House members.
Looking back, Bill Clinton's re-election coalition worked better for his party than Barack Obama's.
Clinton carried the popular vote in the South, as well as the other three regions. Obama lost the popular vote in the South and carried it by only 3 percent in the Midwest.
The presidential election results looked a lot like 2008's. But the farther down the ballot you go, the more the results look like 2010's.