By Michael Doyle

Supreme Court justices raised tough questions Monday about Arizona's use of an independent commission to draw legislative maps, in a case crucial for political operators and reformers in California and beyond.

Conservative justices, in particular, sounded skeptical about independent redistricting commissions that effectively leave state legislators in the lurch.

"It's giving the power to an unelected body of five people," said Justice Antonin Scalia, the most persistent of the critics.

But in a hint of a divided court and a close decision to come, several customarily liberal justices voiced more sympathy for Arizona's use of a general election ballot measure to establish a redistricting system.

"A lot of respect, a lot of deference, has to be given to the states," cautioned Justice Elena Kagan.

While the hourlong argument Monday morning focused on Arizona's independent commission, and touched on everything from 18th-century dictionaries to the musings of Charles Pinckney, one of the lesser-known Founding Fathers, the court's ultimate decision matters concretely to California and other states.

Underscoring California's large stake in the case, former Republican Govs. Arnold Schwarzenegger, Pete Wilson and George Deukmejian filed a brief supporting the independent Arizona commission, as did the California Citizens Redistricting Commission itself.

"Any decision by this court holding that Arizona's redistricting process, enacted by initiative, violates federal law would place in jeopardy California's own redistricting process," the California commission noted in its brief.

The Arizona case revolves around an interpretation of the Elections Clause of the U.S. Constitution, which says that the "times, places and manner of holding elections for Senators and Representatives, shall be prescribed in each state by the legislature thereof."

"The question is, what is the 'legislature'?" noted attorney Seth P. Waxman, a former Clinton administration solicitor general who's representing the Arizona redistricting commission.

Every 10 years, following the decennial census also mandated by the Constitution, states redraw the boundaries for legislative and congressional districts. Flagrant gerrymandering by the majority parties in power has prompted some states to adopt reforms that diminish the partisan outcomes.

In 37 states, legislatures alone still draw the political boundaries. Eleven states use a combination of independent commissions and legislative decision-making. Idaho and Washington state, for instance, use independent commissions but legislators have wide latitude to appoint members.

Arizona and California are the states that rely on the most independent of commissions.

In 2000, 56 percent of Arizona voters approved removing the politically sensitive redistricting job from the state Legislature and turning it over to the five-member Arizona Independent Redistricting Commission.

Once the Arizona commission draws political boundaries, the state's Legislature cannot alter them. The commission members are selected from a narrow pool of candidates prepared by a state board that also handles appellate court appointments.

"What we object to is the permanent wresting of authority from the state Legislature," said attorney Paul Clement, a former President George W. Bush administration solicitor general who's representing the Arizona legislators.

The 14 members of the California Citizens Redistricting Commission are also selected with what the National Conference of State Legislatures described in a brief as "minimal input from the state legislature."

In previous cases, one dating to 1916, the Supreme Court has reasoned that the reference to "legislature" encompasses the legislative process as well as the specific legislative body. Supporters of the Arizona redistricting commission embrace this expansive definition, which can include examples of direct democracy such as a popular referendum.

"If a state constitution says the people have the power, and they can choose a commission or however else they want to do it, isn't that the legislative process?" Justice Sonia Sotomayor said.

Scalia and fellow conservatives, though, pressed back against the idea that the term "legislature" in the Constitution meant something other than legislative body. Justice Anthony Kennedy noted, for instance, that the Constitution originally invested the power of selecting U.S. senators in state legislatures, which Kennedy stressed obviously meant a specific legislative body.

"That history," Kennedy told Waxman, the attorney for the Arizona commission, "works very much against you."

Justice Samuel Alito skeptically pressed Waxman for any other constitutional example "where the term 'legislature' has anything other than the conventional meaning."

"I looked," Scalia said. "I can't find a single one."

Justice Clarence Thomas, as is his custom, was the only one of the nine justices not to speak or ask questions during oral argument. A decision is expected by the end of June.

(c)2015 McClatchy Washington Bureau