WASHINGTON – The Supreme Court ruled Thursday that federal judges have no power to stop politicians from drawing electoral districts to preserve or expand their party’s power, a landmark ruling that dissenters said will empower an explosion of extreme partisan gerrymandering.

The 5-to-4 decision was written by Chief Justice John Roberts and was joined by the court’s other conservatives. It capped decades of debate about whether federal courts have a role in policing partisan efforts to draw electoral districts in the same way the judiciary protects against racial discrimination.

“We conclude that partisan gerrymandering claims present political questions beyond the reach of the federal courts,” Roberts wrote. “Federal judges have no license to reallocate political power between the two major political parties, with no plausible grant of authority in the Constitution, and no legal standards to limit and direct their decisions.”

Both major parties employ gerrymandering to advance their interests, but Thursday’s decision set off alarms among Democrats in particular. They are in charge of far fewer states than Republicans and said the ruling will allow Republicans to set the electoral maps for another decade after the 2020 Census unless Democrats find a way to win locally.

At the court, the decision delivered a dramatic example of how a new justice can create monumental change. For years, the justices have stopped short of overturning a state’s plan because of partisan gerrymandering. But then-Justice Anthony Kennedy thought there might be a future case so egregious it would require protection of voters’ rights.

Kennedy’s replacement – and former law clerk – Justice Brett Kavanaugh needed just a few months to side with fellow conservatives in shutting down those efforts for good.

The decision comes as the public appears to have grown more outraged by the practice. In the last election, voters in five states either limited the power of state legislators to draw electoral lines or took it away from them altogether by creating independent commissions to do the work.

Federal courts have taken a more robust role, too, striking down gerrymanders in battleground states such as Ohio and Michigan.

Partisan gerrymandering is employed by whatever party is in power; the court was considering a Republican-drawn map from North Carolina and one done by Democrats in Maryland. But for that reason, the decision would seem to strengthen Republican hands when new maps are drawn after the 2020 census. The GOP is in control of both the governorship and legislature in 22 states, compared with 14 for Democrats.

“In a democracy, voters should choose their politicians, not the other way around, on Election Day,” said Common Cause National Redistricting Director Kathay Feng. “But the Supreme Court today gave the green light to the most extreme partisan gerrymanders, where legislators openly boasted about their partisan motives, stripping not only the people of North Carolina and Maryland but all Americans, of the right to fair representation.”

KAGAN AUTHORS DISSENT

In his opinion, Roberts did not defend the practice, or say it was constitutional. “Excessive partisanship in districting leads to results that reasonably seem unjust,” he wrote. “But the fact that such gerrymandering is incompatible with democratic principles does not mean that the solution lies with the federal judiciary.”

He was joined by Kavanaugh as well as Justices Clarence Thomas, Samuel Alito and Neil Gorsuch.

Justice Elena Kagan wrote the dissent for the court’s liberals.

“For the first time in this Nation’s history, the majority declares that it can do nothing about an acknowledged constitutional violation because it has searched high and low and cannot find a workable legal standard to apply,” she wrote.

Kagan underscored her disagreement by reading from the bench – at times emotionally – a lengthy excerpt of her dissent.

“The gerrymanders here – and others like them – violated the constitutional rights of many hundreds of thousands of American citizens,” she said.

“The practices challenged in these cases imperil our system of government. Part of the court’s role in that system is to defend its foundations. None is more important than free and fair elections.” She closed by saying her dissent was “with respect but deep sadness.”

She was joined by Justices Ruth Bader Ginsburg, Stephen Breyer and Sonia Sotomayor.

Roberts acknowledged that the court regularly scrutinizes electoral districts for racial gerrymandering and to ensure districts are the same size, to abide by “one-person, one-vote.”

Ferreting out political motivations would be much harder, he said, and intrusive.

“That intervention would be unlimited in scope and duration – it would recur over and over again around the country with each new round of districting, for state as well as federal representatives,” he wrote.

“Consideration of the impact of today’s ruling on democratic principles cannot ignore the effect of the unelected and politically unaccountable branch of the federal government assuming such an extraordinary and unprecedented role,” Roberts wrote.

He said that despite “various requests over the past 45 years,” the court has never struck a state plan as unconstitutional, and that all of those years of consideration have never produced a test that would allow judges to satisfy “the original unanswerable question (How much political motivation and effect is too much?)”

Roberts said that although federal courts should not be involved, voters were not powerless to stop partisan gerrymandering. Florida voters, for instance, amended the state’s constitution to require “fair districts,” he noted, and there were other avenues available.

But he added: “We express no view on any of these pending proposals. We simply note that the avenue for reform established by the Framers, and used by Congress in the past, remains open.”

In fact, Roberts was in the minority in 2015, when the court split 5 to 4 in upholding Arizona’s independent redistricting commission’s power to draw congressional districts.

Kagan countered Thursday that there was good reason for the court to act now.

Advances in data analysis and technology make modern partisan gerrymandering far more extreme and effective, she said.

“While bygone mapmakers may have drafted three or four alternative districting plans, today’s mapmakers can generate thousands of possibilities at the touch of a key – and then choose the one giving their party maximum advantage,” she wrote.

“The effect is to make gerrymanders far more effective and durable than before, insulating politicians against all but the most titanic shifts in the political tides. These are not your grandfather’s – let alone the Framers’ – gerrymanders.”

PERFECT TESTS FOR COURT

The cases from Maryland and North Carolina provided the perfect tests for the court.

In November, a three-judge panel found unanimously that Maryland Democrats had unconstitutionally targeted Republican voters in the state’s 6th Congressional District. The legislature had redrawn the district, which previously stretched across the top of the state, to dip down and take in Democratic strongholds in the Washington suburbs.

After the 2011 redistricting, a Democrat won the seat previously held by a Republican. There was an open election in the district in November, when Democrat David Trone defeated Republican Amie Hoeber by a wide margin.

“The massive and unnecessary reshuffling of the Sixth District, involving one-half of its population and dictated by party affiliation and voting history, had no other cause than the intended actions of the controlling Democratic officials to burden Republican voters by converting the district” into a Democratic one, wrote Judge Paul Niemeyer of the U.S. Court of Appeals for the 4th Circuit.

Rather than redraw the map, as the federal judges had ordered, Maryland’s Attorney General Brian Frosh, a Democrat, appealed to the Supreme Court. That put him at odds with Gov. Larry Hogan, a Republican who won reelection in November and has pushed three times for a constitutional amendment that would have an independent commission redraw boundaries.

Hogan called the court’s ruling “terribly disappointing to all who believe in fair elections.”

“Gerrymandering is wrong, and both parties are guilty,” he said in a statement after the ruling. Hogan said he would reintroduce legislation next year to put the drawing of districts “in the hands of a balanced, fair and nonpartisan commission – instead of partisan politicians.”

The Supreme Court had also sent back the North Carolina case last term, telling a panel of three federal judges to decide whether challengers in that state had the legal standing to bring the case. The judges said they did and also found the legislature’s efforts violated constitutional protections of equal protection and free speech.

The North Carolina legislature “drew a plan designed to subordinate the interests of non-Republican voters not because they believe doing so advances any democratic, constitutional, or public interest, but because, as the chief legislative mapdrawer openly acknowledged, the General Assembly’s Republican majority ‘think(s) electing Republicans is better than electing Democrats,’ ” wrote Judge James Wynn of the U.S. Court of Appeals for the 4th Circuit.

“But that is not a choice the Constitution allows legislative mapdrawers to make,” he wrote.

Wynn was referring to comments from a legislative leader after a previous map was struck down as an example of racial gerrymandering that made clear politics was at the heart of the new map.

“I think electing Republicans is better than electing Democrats,” said Rep. David Lewis, a Republican member of the North Carolina General Assembly, addressing fellow legislators when they passed the plan in 2016. “So I drew this map to help foster what I think is better for the country.”

Lewis proposed drawing the map so Republicans could prevail in 10 of the 13 districts, and that’s what happened when voters went to the polls that year, even though Republican candidates won just 53% of the statewide vote.