For the second year in a row, Alabama has put the Voting Rights Act before the Supreme Court. Last year’s Shelby County v. Holder effectively struck down “preclearance,” a provision of the 1965 law that required states with long histories of racial discrimination to get federal approval before altering voting rules. “50 years later, things have changed dramatically,” wrote the court, insisting that the South’s former logic no longer applies. “The tests and devices that blocked access to the ballot have been forbidden nationwide for over 40 years.”

Now, an Alabama lawsuit over redistricting has reached the nation’s highest court. In Alabama Democratic Conference and Alabama Legislative Black Caucus v. Alabama, the justices will decide whether a 2012 redistricting plan violates the rights of African American voters.

It goes back to the 2010 election, when Republicans gained control of the state legislature for the first time since Reconstruction. The GOP now occupies the governor’s seat, every elected, statewide executive-branch office and supermajorities in both houses. The legislators in this majority are exclusively white.

As is customary, they redrew the state electoral districts for both the house and senate based on the 2010 Census. It was a straightforward effort “to preserve the status quo” — that is, the Republican regime — the state’s attorney told the Supreme Court on Wednesday.

There’s a strange alignment of interests in this case. Alabama Republicans say their new maps protect black voters by preserving majority-minority districts. Their Democratic opponents — in politics and the lawsuit — argue that dispersing rather than concentrating black voters would be the best way to safeguard political participation.

Supreme Court Justice Antonin Scalia said as much to the Democratic Conference lawyer in oral argument: “You realize, I assume, that you’re — you’re making the argument that the opponents of black plaintiffs used to make here … by requiring packing of minorities into certain districts, you’re reducing their influence statewide … that’s the argument the other side used to be making.”