Very depressing. Thanks Obama.
This is the result of the DNC tearing down the 50 state strategy. That 2010 election is going to haunt Democrats for a long time, much like 1958 had affects for Republicans for decades.
Republicans - and particularly technically non-partisan interest groups that support Republicans - very wisely figured out that the "ROI" on downballot legislative races and on judicial races is much higher than chasing after the presidency and governorships.
That strategy really came into full force in the 1990s, but it originated in a letter that Lewis Powell wrote to the US Chamber of Commerce before being nominated to the SCOTUS. Elect "business-friendly" judges in low-level judicial elections that no one else pays attention to; eventually they will serve as the bench for appointments or elections to higher courts. Elect county commissioners, state legislators, etc, and you've got a pipeline of candidates for higher office who you already know will be "reliable."
Democrats very foolishly let their lower level infrastructure coast along on the assumption that unions would do the heavy lifting in the North and the "good ol' boy" network would continue to hold together in the South.
Now they're in the wilderness, and unlike the Republicans in the mid-20th century, the Democrats do not have an army of well-to-do housewives with nothing better to do and true-believing businessmen with plenty of money and connections to throw at their cause.
When democrat's started to decline in rural areas it would be inevitable that they would lose state legislatures much easier than before.
But even if democrats use the anti-incumbency mid-term advantage when a republican is in power. The decline of support in democrat areas will mean even those would just be temporary euphoria.
For some reason its hard for people to accept that the new deal coalition that made the party dominant in the south is dead and in the dumpster for a very long time.