WASHINGTON (AP) — A unanimous Supreme Court says an Arizona commission did not violate the principle of one person, one vote when it redrew the state's legislative districts in a way that created some with more residents than others and improved the prospects for Democrats.
The justices on Wednesday rejected a challenge from a group of Republican voters who claimed the state's Independent Redistricting Commission illegally packed GOP voters into some districts while leaving other Democratic-leaning districts with smaller populations.
A panel of federal judges upheld the new boundaries in 2014, despite finding that some commission members were trying to improve Democratic prospects in the districts. The judges ruled that the commission was trying to comply with a now-nullified provision of the Voting Rights Act.
Officials with the state's redistricting commission argued that slight differences in population were not enough to violate the Constitution's equal-protection clause.
Writing for the Supreme Court, Justice Stephen Breyer said the one-person, one-vote principle "does not demand mathematical perfection." He said the challengers failed to show that "illegitimate considerations were the predominant motivation behind the plan's population deviations."
The high court requires a state's legislative districts to have roughly equal numbers of people, but it has long said those numbers don't have to be exact. Differences of less than 10 percent are presumed constitutional unless challengers can show they are the result of discrimination or other invalid reasons.
State Senate President Andy Biggs — whose wife was in the group that sued — said the decision was "unfortunate."
The commission issued a statement saying it was gratified with the decision, which means the legislative maps will be in place through 2020 elections.
In Arizona, the average population difference in redrawn districts was 2.2 percent, with a maximum difference of 8.8 percent. The plan placed more Republican voters in some districts that already were likely to elect GOP candidates and left other districts with smaller overall populations. Those districts have a greater concentration of Hispanic voters and are considered more likely to vote for Democrats.
Arizona voters created the commission in 2000 to take on the politically charged job of drawing new maps every 10 years, instead of leaving it up to the Legislature.
Ultimately, the plan ended up giving Republicans more than their proportional share of seats in the state legislature.
In a separate case last year, the Supreme Court ruled that cutting lawmakers out of congressional redistricting is not unconstitutional even though state legislatures have the power to set the "times, places and manner" of holding congressional elections.
A third challenge to Arizona's congressional maps remains active in court. That state case involves a challenge to whether the commission followed the Arizona Constitution's guidelines on factors it was to consider while drawing the maps.
Republican Vince Leach, now a member of the state House of Representatives, is one of several voters suing. He said the commission didn't properly consider "communities of interest" — areas with geographic or other ties — while drawing the maps. He specifically cited the state's sprawling 1st Congressional District, which includes Flagstaff and much of the eastern part of the state, and has gone Democratic since the maps were adopted in 2012.
"It's very hard to look at the CD1 map and talk about communities of interest, because it's simply not there," Leach said.
Associated Press writer Bob Christie contributed from Phoenix