WASHINGTON A majority of Supreme Court justices on Tuesday appeared hesitant to weigh in and limit the extent to which lawmakers can take politics into account when drawing electoral districts.

Lawyers representing plaintiffs in a closely watched redistricting case sought to convince the justices that there exists a manageable standard they could use to determine when lawmakers have relied too much on politics while drawing districts. But many of the justices on the high court suggested that what the plaintiffs really wanted was for the court to endorse a proportional representation, where the political makeup of each congressional delegation simply reflects the proportion of votes they get.

The Constitution does not require proportional representation, and the plaintiffs lawyers repeatedly indicated that was not what they were calling for.

The case at the Supreme Court involves two consolidated cases out of North Carolina and Maryland, respectively. In North Carolina , a group of Democratic voters, the state Democratic Party and two good government groups say state Republicans committed a number of constitutional violations when they drew the states current congressional maps in 2016, after a court found they leaned too heavily on race when drawing a previous map. For the 2016 map, Republicans required that their mapmaker draw a plan that continued to give them control of 10 of the states 13 congressional seats. Theyve maintained that significant advantage since, even though the state is closely divided between Republicans and Democrats . Republicans were open about their intentions, but say they were just trying to make it clear that they were drawing their maps based on political, and not racial, considerations .

The plaintiffs say Republicans violated the First and 14th Amendments, which guarantee freedom of association and equal protection of law. They also say the gerrymandered North Carolina map violates Article I of the U.S. Constitution, which says that the people shall choose their representatives and only gives state lawmakers the ability to set the time, manner and place of elections.

In Maryland , Republicans in the states 6th Congressional District say Democrats discriminated against them when they redrew the states districts in 2011. Democrats have admitted to drawing the lines to flip the district from Republican to Democratic control, transforming the Democratic advantage in the states congressional delegation from 6-2 to 7-1. The plaintiffs in the case say that intentional flip amounts to government punishment for their political views. The Supreme Court heard arguments last year at an earlier stage in the case, but declined to weigh in.

Three-judge panels in both North Carolina and Maryland have ruled in favor of the challengers and struck down the congressional maps in place.

The Supreme Court has wrestled with the issue of partisan gerrymandering for decades. While the justices have repeatedly suggested there is a standard for determining when gerrymandering for partisan gain goes too far, they have never outlined what that standard is. Justice Anthony Kennedy was seen as the key swing vote on partisan gerrymandering, but he passed on the chance to do anything about it in two cases that came before the court in his final term. After Justice Brett Kavanaugh replaced Kennedy on the court, many legal scholars believed the chances of the high court doing anything about partisan gerrymandering dwindled significantly .

A Supreme Court ruling in favor of the plaintiffs could potentially reshape American politics. It would set a clear limit on how far lawmakers can benefit their own party when they draw new district lines, forcing more competitive elections. The next round of redistricting, which happens once a decade, will take place in 2021.

Conversely, lawmakers would get a significant amount of power if the Supreme Court says there is no way to determine whether or not a gerrymander is unconstitutional. Freed from the threat of judicial review, lawmakers could use new technology and tools to surgically carve up districts to maximize political advantage. Gerrymandering reform would have to come from laws or ballot initiatives that could limit how politicians draw the map or take it out of their hands entirely. Advocates could also turn to state courts to try and strike down gerrymanders under state constitutions.

Paul Clement, who represented North Carolina lawmakers, warned the justices on Tuesday that if they were to strike down the North Carolina map and announce a standard for partisan gerrymandering, they would be inviting a flood of cases to the Supreme Court. Any voter who was dissatisfied with their representative could bring a case that the Supreme Court would have to hear, he said.

Once you get into the political thicket, you will not get out, Clement said. You will tarnish the image of this court for the other cases where it needs that reputation for independence, so people can understand the fundamental difference between judging and all other politics.

The argument was clearly aimed at Chief Justice John Roberts, who expressed concern during a case last year that if the Supreme Court got involved in gerrymandering, it would be seen as picking winners and losers in elections.

Allison Riggs, an attorney representing the North Carolina plaintiffs, countered Clements argument by telling the court it would suffer a far greater reputational harm if it did not act. Lawmakers in North Carolina bragged about how much gerrymandering they were doing, she said, and if the court didnt weigh in, it would essentially be giving those lawmakers its blessing to discriminate.

When [Republican North Carolina state Rep.] David Lewis says Im going to draw a 10-3 plan and if I could draw an 11-2 plan, I would, the reputational risk of doing something is much, much less than the reputational risk of doing nothing, which will be read as a green light for this kind of discriminatory rhetoric and manipulation in redistricting from here on out, Riggs said.