In 2012, Michael Barone notes, Democrats failed to recoup their 2010 losses downballot.
Between 2008 and 2012, they gained seats in only three states: Delaware, where a popular Republican ran for the Senate in 2010; Maryland, thanks to Democratic redistricting; and California, where a supposedly nonpartisan redistricting commission was dominated by Democrats.
The reapportionment process following the 2010 census cost Democrats some seats because their strong states had relatively little population growth. They have five fewer seats in New York, for example.
The reapportionment effect was strengthened because the 2010 backlash against Democrats gave Republicans control of redistricting in Michigan, Ohio and Pennsylvania, all of which lost seats, and North Carolina, which stayed the same.
As a result, in the 113th Congress, as compared with the 111th, there will be three fewer Democrats from Michigan, six fewer from Ohio, seven fewer from Pennsylvania and four fewer from North Carolina.
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.