The US Supreme Court heard oral arguments on Wednesday in case involving racial gerrymandering claims against South Carolina’s congressional map. The case is an appeal from a three-judge panel decision in the US District Court for the District of South Carolina Columbia Division, which found that South Carolina’s Republican-led legislature’s design of that state’s First Congressional District was an unconstitutional gerrymander in violation of the Fourteenth Amendment’s Due Process Clause because it used race as the predominant factor in drawing the district lines.

John Gore argued on behalf of South Carolina Senate President Thomas Alexander, who is the defendant in the case. Gore argued that the trial court erred when it ruled that the congressional map was an unconstitutional gerrymander because the legislature created the map to increase Republican votes rather than it being a product of racial gerrymandering. Gore focused on the political data used by the legislature, as opposed to racial data.

Justice Clarence Thomas, as well as Justices Sonia Sotomayor and Elena Kagan, noted that the Supreme Court’s standard of review in a case like this is “clear error.” For this standard, a reviewing court generally will only overturn a lower court’s findings if the decision is supported by substantial, credible evidence in the record.

Kagan pushed Gore on this issue, noting that credibility and factual findings of the lower court are given deference under this standard of review—noting that the lower court found the map to be unconstitutional. Gore responded that the lower court made erroneous factual findings as well as legal decisions. Additionally, Gore argued that the lower court did not properly consider testimony during the trial that the state legislature created the First District based on political data.

Justice Samuel Alito noted that under the “clear error” standard of review, a trial court decision is given great deference; however, the standard is not necessarily a “rubber stamp” of approval for the trial court’s findings in every case.

Gore’s argument also focused on the “alternative map” issue in the case. Gore asserted that, in a racial gerrymander case, the challenger is required to submit an alternative map to show that the legislature could have achieved its goals without using race as a motivating factor. Kagan challenged this assertion, stating that there is no alternative map requirement.

Additionally, on the alternative map issue, Chief Justice John Roberts questioned Leah Aden, Senior Counsel for Legal Defense fund and for the plaintiff in this case. Roberts noted that the plaintiff’s lack of an alternative map and direct evidence at trial would be “breaking new ground” in racial gerrymandering precedent.

With Wednesday’s oral arguments concluded, the judges will now take the case under consideration. A decision in the case is not expected for several months.