Activists have long hoped that the Supreme Court would act to rein in partisan gerrymandering — but on Thursday, the justices dashed those hopes.

“Partisan gerrymandering claims present political questions beyond the reach of the federal courts,” Chief Justice John Roberts, joined by the Court’s other four conservatives, wrote in the 5-4 Rucho v. Common Cause decision. “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.”

The upshot of the ruling is that the federal courts cannot strike down district maps because they are designed to help or hurt a particular political party. This will put an end to a trend of the past few years, in which several lower court judges have tried to do just that.

Federal courts still have the power to strike down maps designed to dilute the voting power of racial minorities, or maps that violate the “one person, one vote” principle. Supreme Court precedent in both areas is well established, and Thursday’s decision did nothing to change it.

But the Court had long been vague about whether district maps could be unconstitutionally gerrymandered on partisan grounds. That is: Can Republicans draw maps to elect as many Republicans as possible? Can Democrats do the same? Or could such measures violate, say, the Constitution’s Equal Protection Clause or the First Amendment?

The Supreme Court had never struck down a district map for those reasons. But since at least the 1980s, and especially while Anthony Kennedy was on the Court, some justices left open the possibility that they could. Kennedy mused in a 2004 concurring opinion that there might be some sort of standard or test the Court could come up with to determine how much partisan gerrymandering is too much. He just hadn’t heard what it might be.

But now that Kennedy has been replaced by Brett Kavanaugh, the Court has ended the vagueness and punting. Roberts and the conservatives are definitively saying: If you hate partisan gerrymandering, too bad — you can forget about using the federal courts to try to do something about it.

The practical implication is that one potential tool that could be used to check the power of state legislatures to gerrymander on partisan grounds — lawsuits brought in federal courts — no longer exists. States can still pursue their own efforts to reform the rules, but on the whole, this strengthens the power of state legislators to do what they want with their boundaries.

Activists have long hoped the Supreme Court would restrict partisan gerrymandering

Since the 1960s, the Supreme Court has established a great deal of precedent around what, exactly, states can and cannot do when it comes to drawing both congressional and state legislative district boundaries. For instance, maps can be struck down for deviating too far from the “one person, one vote” principle. The Court has found that racial gerrymandering can violate the Constitution as well.

But the high court has never stepped in to intervene on partisan gerrymandering: when district boundaries are drawn to give one party an advantage over the other.

So does partisan gerrymandering violate the United States Constitution? In recent decades, many activists and academics have tried to argue that it can. And beginning in 2016, some lower court federal judges began to agree with them, striking down such maps under the reasoning that they violate the Equal Protection Clause or the First Amendment.

Yet the Supreme Court has long been wary of the issue. The conservative justices have expressed skepticism that they could come up with a workable standard for determining how much partisan gerrymandering is too much. (The Constitution gives the redistricting power to state legislatures — who are, after all, politicians.) And though the Court’s four liberals have been eager to try to set such a standard, they’ve lacked a crucial fifth vote to join them.

Last year, a big partisan gerrymandering case — Gill v. Whitford, about the Wisconsin state legislature map — did make it to the Court. But it ended in a punt. The justices ruled that the plaintiffs didn’t have standing to bring their lawsuit. However, they also essentially laid out a road map for how to better establish standing, and sent the case back for reargument.

That Wisconsin case didn’t make it back to the Supreme Court in time for Thursday’s decision. Instead, two other partisan gerrymandering cases reached the Supreme Court this term, from North Carolina and Maryland.

The background for the North Carolina and Maryland gerrymandering cases

The North Carolina case, Rucho v. Common Cause, is about whether the state’s congressional map is an unconstitutional partisan gerrymander.

It’s the latest development in a saga that’s spanned nearly a decade. During the last round of redistricting, in 2011, North Carolina Republicans adopted a new map that heavily favored the GOP. Opponents filed suit, arguing that the map was drawn to dilute the voting power of black North Carolinians (by packing many into just two of the state’s 13 districts). Eventually, a majority of Supreme Court justices agreed, finding that this was an unconstitutional racial gerrymander.

But North Carolina Republicans had what they thought was a clever solution. In redrawing a new map, rather than focus on race, they’d make an even more GOP-favored map, by focusing on partisanship. “I propose that we draw the maps to give a partisan advantage to 10 Republicans and three Democrats,” one state legislator involved in the map-drawing said in 2016.

The new map helped the state’s Republican delegation survive the Democratic wave year in 2018 (though one Republican candidate’s apparent victory was invalidated due to apparent election fraud). But naturally, the matter ended up back in court, with plaintiffs arguing the GOP carried out an unconstitutional partisan gerrymander. A lower-court panel ruled last year that it indeed was such a thing, writing that the map’s “invidious partisanship” violated the Constitution. But an appeal brought the case to the Supreme Court.

Separately, the Maryland case, Lamone v. Benisek, is about a partisan gerrymander that hurt Republicans. Democrats controlled the redistricting process in Maryland in 2011, and they carefully packed GOP voters into just one of the state’s eight districts (the first district, in the east).

Since then, Democrats have easily won all seven of the other districts in the state. A lower court panel found that this was indeed an unconstitutional partisan gerrymander — but this too was sent to the Supreme Court on appeal. The justices paired it with the North Carolina case, because similar issues were at play.

What the Court decided

In the end, Roberts argued that there was no good way for the courts to determine how much partisan gerrymandering is too much — and he said that shouldn’t be their job, anyway.

“What the appellees and dissent seek is an unprecedented expansion of judicial power,” Roberts wrote. He continued:

We have never struck down a partisan gerrymander as unconstitutional — despite various requests over the past 45 years. The expansion of judicial authority would not be into just any area of controversy, but into one of the most intensely partisan aspects of American political life. 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. 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 made several other points:

That the Constitution’s framers were well aware of the practice of partisan gerrymandering, and never suggested that the courts should try to prevent it

That previous Supreme Court decisions have clearly established that some amount of partisan gerrymandering is acceptable, meaning the problem is determining when the practice goes too far

And that he still has never heard a neutral and convincing standard that the courts could apply in determining how much partisan gerrymandering is “too much”

Roberts also wrote that supporters of the courts intervening here “invariably sound in a desire for proportional representation” — the idea that if a certain percentage of the state’s voters support one party, it’s unfair to have that diluted by district boundaries. But he argued that such unfairness is inherent to winner-take-all elections:

There is a large measure of “unfairness” in any winner-take-all system. ... The one-person, one-vote rule is relatively easy to administer as a matter of math. The same cannot be said of partisan gerrymandering claims, because the Constitution supplies no objective measure for assessing whether a districting map treats a political party fairly. It hardly follows from the principle that each person must have an equal say in the election of representatives that a person is entitled to have his political party achieve representation in some way commensurate to its share of statewide support.

“Excessive partisanship in districting leads to results that reasonably seem unjust,” Roberts acknowledged. But, he said, that “does not mean that the solution lies with the federal judiciary.” So both the North Carolina and Maryland district maps will remain in place.

Justice Elena Kagan wrote a fiery dissent, saying that partisan gerrymanders in these cases “deprived citizens of the most fundamental of their constitutional rights: the rights to participate equally in the political process, to join with others to advance political beliefs, and to choose their political representatives.”

She added: “In so doing, the partisan gerrymanders here debased and dishonored our democracy, turning upside-down the core American idea that all governmental power derives from the people.” But she lacked that crucial fifth vote that would make her opinion a majority — so the conservatives carried the day.