This is a really big deal. SCOTUS rules in favor of the people of Arizona vs. their own state government.
In response to complaints that the state legislature was engaging in partisan gerrymandering of congressional districts, Arizona voters approved an independent commission to draw district lines in a 2000 ballot initiative. The commission has two Republicans and two Democrats, who legislative leaders choose from a list composed by the state's Commission on Appellate Court Appointments, in addition to a chairman who may not be a member of either party.
Republican legislators sued after the 2012 election, arguing that they shouldn't be completely cut out of the district-drawing process.
The case before the Supreme Court -- Arizona State Legislature v. Arizona Independent Redistricting Commission -- hinged on one word: "legislature." It arose out of a debate over the Constitution's elections clause, which dictates that the "times, places, and manner" of federal elections "shall be prescribed in each state by the legislature thereof."
The court's majority recognized how a ruling against the commission would affect elections in states beyond Arizona.
"Banning lawmaking by initiative to direct a State’s method of apportioning congressional districts would not just stymie attempts to curb gerrymandering," it wrote. "It would also cast doubt on numerous other time, place, and manner regulations governing federal elections that States have adopted by the initiative method. As well, it could endanger election provisions in state constitutions adopted by conventions and ratified by voters at the ballot box, without involvement or approval by 'the Legislature.'"