The U.S. Supreme Court is expected to rule either Friday or Monday on the Constitutionality of Arizona’s method of drawing congressional district boundaries. The decision could also impact a handful of other states with similar systems.

The voter-approved Independent Redistricting Commission was created in 2000. The five-member panel is tasked with using census data to redesign the state’s congressional districts.

Attorneys representing the Republican majority in the state legislature have challenged the constitutionality of this panel, arguing that only elected bodies can have that responsibility.

If the Supreme Court Justices agree, redistricting authority would be shifted to the Arizona Legislature.