In a 5-4 vote, the U.S. Supreme Court has rejected arguments that the state lawmakers had the exclusive power to draw congressional district boundaries and has upheld the right of the voters to create the Arizona Independent Redistricting Commission.

You can read the entire opinion here, but Ruth Bader Ginsburg, writing for the majority, notes:

Invoking the Elections Clause, the Arizona Legislature instituted this lawsuit to disempower the State’s voters from serving as the legislative power for redistricting purposes. But the Clause surely was not adopted to di¬minish a State’s authority to determine its own lawmak-ing processes. Article I, §4, stems from a different view. Both parts of the Elections Clause are in line with the fundamental premise that all political power flows from the people. McCulloch v. Maryland, 4 Wheat. 316, 404– 405 (1819). So comprehended, the Clause doubly empow¬ers the people. They may control the State’s lawmaking processes in the first instance, as Arizona voters have done, and they may seek Congress’ correction of regula-tions prescribed by state legislatures.

The people of Arizona turned to the initiative to curb the process of gerrymandering and, thereby, to ensure that Members of Congress would have "an habitual recollection of their dependence on the people." The Federalist No. 57, at 350 (J. Madison). In so acting, Arizona voters sought to restore "the core principle of republican government," namely, "that the voters should choose their representatives, not the other way around.." Berman, Managing Gerrymandering, 83 Texas L. Rev. 781 (2005). The Elections Clause does not hinder that endeavor.

Republican state lawmakers were so sure they were going to win back the power to gerrymander maps in their own favor that they had already hired a consulting firm to draw new districts, while Democrats were considering various legal actions to keep the current boundaries—which include four districts that are heavily Republican, two districts that are heavily Democratic and three districts that are competitive—in place for the 2016 elections cycle.

Congresswoman Ann Kirkpatrick (D-CD1), who is giving up her competitive seat in order to challenge Sen. John McCain next year, says she is "thrilled that the will of Arizona voters was affirmed today in our nation’s highest court." Kirkpatrick continues: 

In 2000, when voters created the independent redistricting commission, their goal was to give power back to the people and end the back-room deals by a handful of politicians. Today’s ruling protects that goal and closes the door once and for all on the back-room dealmakers and their power grabs. I stand with Arizona voters on this and other efforts to empower and engage them in our political process.

Congresswoman Martha McSally (R-CD2), who represents one of the competitive districts, reacts:

I respect the Court’s decision today, and look forward to continuing to represent the people of Arizona’s Second District. I was sent to Congress with a job to do, and will continue to work tirelessly with the focus of expanding economic opportunity and improving security for Southern Arizonans.

Arizona House Speaker David Gowan (who was rumored to be drawing up a friendly congressional district for himself) and Senate President Andy Biggs expressed their disappointment with the ruling in a written statement:

We are disappointed that the Supreme Court has decided to depart from the clear language of the Constitution. The Framers selected the elected representatives of the people to conduct congressional redistricting. It’s unfortunate that the clear constitutional design has been demolished in Arizona by five lawyers at the high court.

Congressman Raul Grijalva (D-CD3) says the decision "validated the demands of Arizonans to leave partisan politics behind when it comes to drawing up Congressional Districts. Elections are not games for politicians to rig, and this court decision makes clear that public officials cannot trump the will of the people in an attempt to stack the electoral map in their favor.” He adds:

The voice of the people should always be respected – especially by those entrusted by the voters with public office, Our state legislature should have to adhere to the standards passed by our voters. Not only did this shameful power grab threaten the impartiality of our elections in Arizona, but if the legislature had succeeded, this could have set a legal precedent to invalidate all voter-initiated election reform laws across the country. Thankfully, we are instead left with a strong reminder of the most precious power Americans have in our Democracy: their voice.

Arizona House Democratic Leader Eric Meyer cheers the decision:

Arizona voters said that they want an open, transparent and fair redistricting process, which is why they established the Independent Redistricting Commission. The Supreme Court decision today protects the will of the voters and will help prevent partisanship and political ambition from influencing the redistricting process. Our state is better served by having a body, independent of the Legislature, in charge of this important task.

Sam Wercinski, Arizona Advocacy Network’s Executive Director, says the "decision affirms the authority of voters to pass or reject laws at the ballot box. Wercinski adds:

A different decision, one that favored self-interested politicians over the state’s citizens, would have been a devastating blow to democracy in Arizona. The IRC was created by the people, and given a responsibility to serve the people’s best interests regardless of which political party may control government when redistricting occurs. Today’s decision strengthens the foundation that our state was built on.

More reaction to come.