The ruling, delivered by a 6-3 majority, comes as a win for Republican mapmakers who argue that politics, rather than race, were the primary factor in drawing the district lines.

The district in question is Congressional District 1, currently represented by Republican Rep. Nancy Mace. A three-judge district court panel had previously ruled that Republican lawmakers improperly used race in designing the district, prompting the Supreme Court to reassess the case.

Writing the majority opinion, Justice Samuel Alito stated that the district court's findings were "clearly erroneous." The conservative justices argued that race and politics are closely linked in South Carolina, and the voters challenging the boundaries failed to provide direct evidence of a racial gerrymander.

Justice Elena Kagan, joined by Justices Sonia Sotomayor and Ketanji Brown Jackson, penned a dissenting opinion, accusing the majority of selectively considering evidence and hindering racial-gerrymandering cases. Kagan stressed that the state must redraw District 1 without targeting African-American citizens.

The request by South Carolina Republicans and the state chapter of the NAACP to issue the ruling before January 1, 2024, to provide clarity for the upcoming elections was not fulfilled. As a result, the three-judge district court panel agreed to pause its decision to invalidate the district lines until March, allowing the state to use the allegedly racially gerrymandered map for the upcoming congressional contests, with statewide primaries slated for June 11.

The plaintiffs argued that the redistricting process in 2021, led by Republican lawmakers, aimed to give the district a stronger Republican advantage. More than 140,000 residents were shifted out of Congressional District 1 and into District 6, held by Democratic Rep. Jim Clyburn. The district court panel found that the Republican mapmakers set a target of 17% Black voting-age population in District 1 and moved over 30,000 Black residents into District 6 to achieve a more Republican-leaning district.

The Supreme Court majority, however, dismissed the district court's focus on the movement of Black voters between the districts, claiming that the correlation between race and partisan preferences negates the argument that race, rather than politics, drove the legislature's decisions.

The decision has drawn strong reactions from both sides. Critics argue that the ruling imposes a higher burden of proof for plaintiffs alleging racial gerrymandering and signals to lawmakers that they can use race as a proxy to meet their partisan objectives. Supporters emphasize that the Supreme Court upheld the role of politics in the redistricting process, as mandated by the 2019 ruling that federal courts could not hear claims of partisan gerrymandering.

The battle over Congressional District 1 is the latest in a series of redistricting disputes that have reached the Supreme Court following the 2021 redistricting process. The court's decision not to allow the use of a congressional map drawn by Republicans in Alabama in the upcoming elections, due to a likely violation of federal law, and the subsequent selection of a new map in Alabama that grants a second district with a significant Black electorate, exemplify the impact of recent legal challenges on redistricting outcomes. Similar disputes over voting lines in Georgia, Louisiana, and Florida have also unfolded, potentially affecting the balance of power in the November elections when Republicans aim to retain control of the House.

This ruling serves as a reminder of the ongoing debates surrounding redistricting, and the intersection of race and politics in shaping electoral boundaries across the United States.