The Arizona Legislature sued in 2012, arguing that the creation of the AIRC violated the Elections Clause of the U. S. Constitution, which says “The Times, Places and Manner of holding Elections for Senators and Representatives shall be prescribed in each State by the Legislature thereof; but the Congress may at any time by Law make or alter such Regulations.” The United States District Court for the District of Arizona, dividing two to one, rejected the Legislature's complaint, finding that prior Supreme Court decisions “demonstrate that the word ‘Legislature’ in the Elections Clause refers to the legislative process used in [a] state, determined by that state's own constitution and laws,” and that the lawmaking power in Arizona “plainly includes the power to enact laws through initiative”.

While exercise of the initiative was not at issue in this Court’s prior decisions, there is no constitutional barrier to a State’s empowerment of its people by embracing that form of lawmaking."

Justice Scalia explained at length why he would not have granted standing in this case, then added "[n]ormally, having arrived at that conclusion, I would express no opinion on the merits unless my vote was necessary to enable the Court to produce a judgment.

In the present case, however, the majority’s resolution of the merits question ('legislature' means 'the people') is so outrageously wrong, so utterly devoid of textual or historic support, so flatly in contradiction of prior Supreme Court cases, so obviously the willful product of hostility to districting by state legislatures, that I cannot avoid adding my vote to the devastating dissent of the Chief Justice."

Justice Thomas contrasted the court's support for direct democracy in this case with the overturning of many state voter referendums opposing same sex marriage in Obergefell v. Hodges,[4] decided days earlier.

On June 30, 2015, the Court issued a grant, vacate, remand order in the case, in which it granted the petition, vacated the decision below by the Tenth Circuit, and remanded it to the lower court for reconsideration in light of Arizona State Legislature v. Arizona Independent Redistricting Commission.