Forestalling gerrymandering has other, less concrete benefits as well. According to Justin Levitt, a professor at Loyola Law School who studies redistricting (and who has filed a brief in support of preserving the commission in Arizona), independent commissions can lead to more accurate representations of voters' interests. That's because partisan redistricting often fragments districts so much that the people in them don't have a lot in common. "If there's a community, there's a sense of what that community might want," Levitt argues. "That isn't the case if all [the people in the district] have in common is a political affiliation."
The upcoming Supreme Court case rests on language in the Constitution that requires state legislatures to determine the boundaries of congressional districts. Article 1, Section 4 declares that the "times, places, and manner" of federal elections are regulated by state legislatures, unless Congress says otherwise.
But the Constitution's language is ambiguous, says Levitt. "The Court hasn't interpreted that language literally in cases in the past," he says. In previous instances, the "legislature" has been understood more broadly to include the governor and also referendum power.
The Coolidge Reagan Foundation, a conservative group chaired by Shaun McCutcheon of McCutcheon v. FEC fame, has filed a brief in support of the Arizona Legislature. However, the concept of independent redistricting commissions does enjoy bipartisan support. Last month, three former California GOP governors submitted a brief in support of independent redistricting. And a group of 20 members of Congress—11 Democrats and nine Republicans—has also filed a brief in support of maintaining the status quo in Arizona.
This isn't the first time Congress has waded into independent redistricting: Democratic Rep. Alan Lowenthal of California introduced a House bill last year to bring independent commissions to all states. And in 2013, Democratic then-Rep. Bruce Braley of Iowa sponsored a bill that would have given independent commissions the ability to draw district maps, with legislatures getting final approval powers. Neither effort received much support.
A ruling striking down Arizona's law could be far-reaching or it could be more limited, says Levitt. It could apply to just a handful of states, or it could affect numerous states where entities other than the legislature play a role in redistricting—for instance, states where courts have the ability to revise gerrymandered districts. If "the Court sides with the Arizona commission, states generally have all the options on the table," Levitt explains. "If the Court sides with the Arizona Legislature, depending on how they rule, it could affect a few states or the vast majority of them."
Levitt emphasizes that there isn't a one-size-fits-all commission that would serve all states' needs. Still, the benefits of somehow limiting the gerrymandering power of elected officials are undeniable. The question now is whether the Supreme Court will allow this practice to continue.