Jun 29, 2015:
In the case of Arizona State Legislature v. Arizona Independent Redistricting Commission, by a vote of 5-4 the U.S. Supreme Court ruled in favor of the Arizona Independent Redistricting Commission. Judges Sotomayor, Kagan, Ginsburg, Breyer, and Kennedy, voted in favor, and judges Roberts, Scalia, Alito, and Thomas ruled against.
Read the 81-page Arizona State Legislature v. Arizona Independent Redistricting Commission "Opinion of the Court" here.
On November 7, 2000, Arizona voters approved Arizona Proposition 106 (also known as the Constitutional Amendment Relating to Creation of a Redistricting Commission). That approval amended the Arizona State Constitution which resulted in the creation of the Arizona Independent Redistricting Commission, giving it the power to re-draw the state's legislative and congressional district lines after every census, and taking that power away from the Arizona State Legislature. The Arizona State Legislature argued that Section 4 of Article I of the United States Constitution granted the power of drawing congressional district lines to the Arizona State Legislature, challenging the voter-approved passage and implementation of Arizona Proposition 106.
Source:
"Arizona Creation of a Redistricting Commission, Proposition 106 (2000)". BallotPedia. Retrieved 2015-07-04.
Liptak, Adam. (June 29, 2015). "Supreme Court Rebuffs Lawmakers Over Independent Redistricting Panel". The New York Times. Retrieved 2015-07-04.
Sanders, Rebekah L.; Pitzl, Mary Jo. (June 29, 2015). "Supreme Court upholds Arizona political map". The Arizona Republic. Retrieved 2015-07-04.