Washington (AFP) - The US Supreme Court appeared sharply divided on Tuesday as it heard a politically charged case about gerrymandering, the dark art of drawing electoral maps to extract partisan advantage.
The nine justices of the nation's top court seemed split along ideological lines as they heard arguments in a case that could reshape the future of American politics.
The five conservative justices appeared inclined to let the states continue to work out solutions to the vexed question, which has sparked calls for reform from public figures including action star and erstwhile politician Arnold Schwarzenegger.
Justice Neil Gorsuch, who was appointed by Republican President Donald Trump, noted that some 20 states have already taken measures to crack down on gerrymandering.
"Why should we weigh into this?" Gorsuch asked.
The four liberal justices, however, seemed ready to wade in.
The latest gerrymandering cases to come before the court are from North Carolina, where Republican lawmakers are accused of devising electoral maps to favor themselves, and Maryland, where Democrats have allegedly done the same.
Under the US constitution, congressional seats are redrawn every decade during census years to account for population growth.
But the party in power at the time frequently tilts the playing field to their own advantage by carving out districts packed with voters that benefit their candidates.
In the North Carolina case, the Republican authors of the 2016 congressional map explicitly stated their intentions.
- 'People are bragging' -
"I propose that we draw the maps to give a partisan advantage to 10 Republicans and three Democrats," said a member of the redistricting committee, "because I do not believe it's possible to draw a map with 11 Republicans and two Democrats."
The plan was successful: in the 2018 congressional vote, Democrats won a majority of votes statewide, but only three of the 13 districts.
The Maryland case hinges on one rural district which remained in the hands of the same Republican for 20 years. It underwent a redistricting exercise in 2012, which added more urban voters, and flipped to the Democrats two years later.
Elena Kagan, one of the four liberal justices, said it appeared wrong for the court to "leave all this to professional politicians" who "have an interest in districting according to their own partisan interests."
"People are bragging," Kagan said, "because they think it's perfectly legal to do so."
Another liberal justice, Stephen Breyer, said he feared the amount of gerrymandering would only get worse over time.
"Politicians consider politics, yes," Breyer said. "Our problem is 'When is it too much?'"
"There was not that much gerrymandering in the past compared to what there might be with computers in the future," he went on. "What I am trying to do is to figure out if there is a way to catch real outliers."
- 'Workable standard' -
Gerrymandering came before the Supreme Court in cases related to Wisconsin and Maryland last year, but both were kicked back to lower courts on procedural grounds.
When it last considered such a case in 2004, the court voted 5-4 against reforming the system.
Judge Anthony Kennedy tipped the balance by voting against reform -- but said he might be persuaded in future if courts were presented with a "workable standard" by which to assess whether a district had been gerrymandered.
With Kennedy's retirement however, the make-up of the court has changed.
His replacement is conservative Justice Brett Kavanaugh, who was appointed by Trump last year.
Kavanaugh appeared somewhat sympathetic on Tuesday to opposing gerrymandering in extreme cases.
At the same time, he said the US Constitution does not say there has to be "proportional representation" in the US Congress.
"If gerrymandering is defined as a deviation from proportional representation, the Constitution does not contain such a guarantee," Kavanaugh said.
Schwarzenegger, the former Republican governor of California best known for playing ruthless cyborg assassin "The Terminator," joined protestors outside the Supreme Court on Tuesday to argue for an end to gerrymandering.
"We must terminate gerrymandering," Schwarzenegger said. "This scam has been going on for too long.
"Both parties have been gerrymandering," he said. "It is a national disgrace, a national scandal."
The portmanteau "gerrymander" was coined after Elbridge Gerry, the governor of Massachusetts, who signed a law in 1812 that created a voting district in Boston that resembled a salamander.