That’s how a swing state with a fairly even political divide will end up being represented in Congress next year by 12 Republicans and four Democrats.

No wonder Boehner feels confident that he can stay Speaker ofvthe House.

How long before redistricting can happen again?

 every decade

So we're talking 2020? Or can it happen sooner?

gerrymandering at its finest. 

 2020

 Both parties do this gerrymandering as much as they can, whenever they can. The imbalance with voter desires, and creation of 'safe' distrcits for both parties, removes a lot of the competition and dynamism that could help check permanent political classes.

California props 11 (2008) and 20 (2010) gave a citizen's commission power to redistrict, an improvement, but one which still wasn't completely immune to pro operator manipulation, as this bit of research highlights: ProPublica: How Democrats Fooled California's Redistricting Commission.

I think a more radical reform is necessary. One possibility might be "votermandering": letting voters pick any 'nearby' district to vote in, where "nearby" might be the 3 nearest, or any district neighboring the one the process assigned them. Then at some point the manipulator's fancy map-carving still can't prevent large constituencies from electing favored candidates somewhere nearby. (Geography is a lot less important nowadays, anyway.)