The New York Times has an article from the weekend that essentially concludes that the Voting Rights Act (VRA) has resulted in the congressional and state redistricting lines being essentially divided by ethic groups and boundaries established by race.  An excerpt:

With few exceptions, the decision to create or protect a minority district was also a decision about whether it would elect a Republican or a Democrat. Talk about walking on eggshells — every conversation or argument about the maps teeters between politics and race.

This year’s elections will clear up the remaining questions. Mr. Doggett is the last Anglo Democrat in the Congressional delegation who wasn’t elected in a minority opportunity district. If he wins re-election, it will be in a Latino district. (Representative Gene Green, Democrat of Houston, also an Anglo, has represented a Latino district for years.)

The only genuine swing district on the Congressional map is District 23, where Representative Francisco Canseco, Republican of San Antonio, will face the winner of a Democratic primary that could include former United States Representative Ciro Rodriguez, whom Mr. Canseco beat in 2010. That’s a test of whether Republicans can hold a minority district.

United States Representative Blake Farenthold, Republican of Corpus Christi, got a district with a Republican voting history but where a majority of the voters are either black or Latino. That’s another political test tube.

Republicans can’t increase their already stout majorities without winning minority votes or getting rid of the law that protects minority voters. And Democrats have to figure out a way to win in districts drawn by the opposition.