On January 24, a 3-judge U.S. District Court heard arguments in Arizona State Legislature v Arizona Independent Redistricting Commission, 2:12cv-1211. Arizona U.S. House district boundaries are drawn by an independent commission. The legislature filed the lawsuit to regain its old ability to draw the district lines. The legislature argues that Article One, section 4 of the U.S. Constitution says that only state legislature can write election laws concerning congressional elections. See this article about the hearing.