Multiple courts around the country have determined this year that redistricting efforts can be so partisan that they violate the Constitution. The U.S. Supreme Court doesn't appear to be in a hurry to issue such a finding.

The court has now heard two partisan gerrymandering cases this term, with a third waiting in the wings. Although the first case, involving Assembly maps in Wisconsin, was heard in October, the court has yet to issue a ruling. The court heard an oral argument in the second case, which involves Maryland's congressional map, on Wednesday. The court may also consider North Carolina's congressional map.

The Maryland case, known as Benisek v. Lamone, turns on the question of whether Maryland's redistricting process, which eliminated the Republican advantage in one of the two congressional seats the party had controlled, violated the First Amendment rights of GOP voters who were being discriminated against because of their past voting history.

The Wisconsin case, known as Gill V. Whitford, pursued a different theory, known as the efficiency gap, which measures how many votes are "wasted." According to this argument, all votes cast for a losing candidate and any votes for the winner beyond the 50 percent-plus-one needed to win are considered wasted.

Wednesday's argument suggested that a number of justices -- perhaps a majority -- would like to set a standard for when partisan gerrymandering crosses the constitutional line.

"However much you think is too much partisanship, this case is too much," Justice Elena Kagan said.

But the series of hypothetical scenarios the justices presented to lawyers arguing the case made it clear there was no ready consensus about how to define what an unconstitutional partisan gerrymander would look like.

"It seems like a pretty clear violation of the Constitution to have deliberate extreme gerrymandering," said Justice Stephen Breyer, "but is there a practical remedy that won't get judges involved in dozens and dozens and dozens of very important political situations?"

Justice Samuel Alito suggested that it would be impossible to set a legal standard for determining how much politics would be too much in a process that is itself inherently political.

"I really don't see how any legislature will ever be able to redistrict," Alito said. "Hasn't this court said time and again you can't take all consideration of partisan advantage out of districting?

Justice Anthony Kennedy is widely considered to be the swing vote in these cases. As happened in the Wisconsin argument, he asked Maryland Solicitor General Steven Sullivan whether it would be unconstitutional to have a provision explicitly calling for party to be the predominant consideration in redistricting. Sullivan conceded that would be discriminatory. Kennedy then asked if that was the intent, then why would stopping shy of stating that outright make it legal?

"So, if you hide the evidence of what you're doing, then you're going to prevail?" Kennedy said.

Kennedy set the stage for the current legal fights with an opinion in Vieth v. Jubelirer, a 2004 Pennsylvania case. Back then, Kennedy wrote that there could be such a thing as an unconstitutional partisan gerrymander, but only if the courts had a "workable standard" for determining when mapmakers had crossed that line.

While the political world waits to see whether the Supreme Court can agree on such a test, other courts have begun striking down maps as unconstitutional partisan gerrymanders. In January, the Pennsylvania Supreme Court threw out the commonwealth's congressional map, producing a new map itself when the legislature and the governor were unable to reach agreement. The U.S. Supreme Court refused to consider blocking the state court's decision.

Also in January, a federal panel threw out the congressional map in North Carolina, finding that it violated the equal protection clause under the 14th Amendment.

"We agree with plaintiffs that a wealth of evidence proves the General Assembly's intent to 'subordinate' the interests of non-Republican voters and 'entrench' Republican domination of the state's congressional delegation," wrote Judge James Wynn.

The U.S. Supreme Court issued a stay, blocking the lower court's ruling from taking effect and keeping the state's congressional map in play for this year's elections. The Supreme Court is expected to decide next month whether it will hear the case.

On Wednesday, Justice Breyer suggested rolling up the three cases -- involving the Maryland, Wisconsin and North Carolina maps -- into a fresh oral argument to be heard next term. That way, all the different legal theories and potential standards for partisan gerrymandering could be considered together, he said. None of the other justices jumped at that suggestion.

The question remains about exactly how far partisan mapmakers would have to go in pressing an advantage for their side before they violated the Constitution. In both Maryland and North Carolina, politicians involved in the effort made their intentions pretty clear.

"As the elected governor, I did my duty within the metes and bounds” of Maryland law, former Gov. Martin O'Malley, a Democrat, said in a deposition last year. He added that if the district in question "would be more likely to elect a Democrat than a Republican, yes, this was clearly my intent."

North Carolina state Rep. David Lewis, a Republican who chaired the state House redistricting committee, said at a hearing in 2016 that he drawn a "political gerrymander," which he contended was legal.

"I think electing Republicans is better than electing Democrats, so I drew this map to help foster what I think it better for the country."

Asked why he created a map that created a 10-3 Republican advantage in the congressional delegation of a state that is fairly evenly divided, Lewis said, "because I do not believe it's possible to draw a map with 11 Republicans and two Democrats." 

Not all mapmakers are so candid. That's why the Supreme Court is still looking for a way to measure when partisan gerrymanders are unconstitutional. 

"We'll never have such a record again," Justice Breyer said Wednesday. "I mean, the people who do the gerrymandering are not stupid."

This appears in the Politics newsletter. Subscribe for free.