(Reuters) – After the 2020 Census, South Carolina’s Republican-led legislature assured Democratic lawmakers and the public that they would carry out a fair and transparent process to redraw the state’s seven Congressional election districts.

A year earlier, the U.S. Supreme Court had decided for the first time that partisan gerrymandering is lawful, permitting lawmakers to manipulate electoral maps to gain an edge for their party. Electoral maps based on race are impermissible, the court said, but those designed to give a political party an advantage are lawful.

G. Murrell Smith, the Republican speaker of the state House of Representatives, told me in a statement that he disagrees that the House intentionally drew racially biased maps, and said he expects an appeal.

The court cited “striking” evidence of racial sorting produced in several days of testimony and a copious court record that included lawmakers’ text messages.

Roberts didn’t respond to requests for comment.

The case was filed against lawmakers by the state conference of the NAACP and other advocacy groups.

John Cusick, a lawyer with the NAACP Legal Defense and Educational Fund who represented the plaintiffs, told me the ruling is a significant win for voters that “brings South Carolina closer to fair and accurate representation.”

The Republican defendants clearly relied on the landmark 2019 Supreme Court decision that approved partisan gerrymandering, a 5-4 ruling split along political lines.

“You can take race out of politics,” conservative Chief Justice John Roberts said at the time, “but you can’t take politics out of politics.”

The statement had the same ring of certitude as a 2013 decision in which Roberts wrote that certain legal protections for minority Americans have outlived their usefulness because “[o]ur country has changed.”

Those rulings fall in line with another 2021 decision that made it easier to discriminate via racially targeted voting restrictions. And, altogether, they opened the door to partisan and racially biased laws and other schemes to restrict voting around the country, from prohibiting access to water, to outright coercion and intimidation.

South Carolina was one of several former confederate states required by law to submit their electoral plans to the federal government for review before enactment, until the court gutted those provisions of the Voting Rights Act in 2013.

The state has seen significant growth in the Black voting age population in some of its largest communities since the 2010 census, including in the coastal First District that spans Charleston, its largest city, and the state’s unique Gullah and Geechee corridor.

The district was a Republican stronghold for nearly 40 years, but became competitive when residents elected a Democrat in 2018. (It flipped back to Republican control in 2020).

Republicans began developing the state’s new map in 2021, and they largely excluded the public and Democratic lawmakers from the process, according to the NAACP and testimony by witnesses on both sides of the case.

The legislature received and considered input without disclosing those proposed maps outside of a tight-knit cadre of Republican legislators and aides who controlled the process, according to case testimony and an Oct. 4 report by The State in Columbia, South Carolina.

That included requests from South Carolina representatives in the U.S. House, and a draft map that was submitted via staffers’ personal email addresses by the National Republican Redistricting Trust, a group that coordinates Republican mapping efforts and has been affiliated with a number of nationally prominent right-wing conservatives.

Those facets of the process were entirely unknown until Republican lawmakers and aides were issued subpoenas and asked questions under oath.

The National Republican Redistricting Trust didn’t respond to a request for comment.

Ultimately, the legislature rendered tens of thousands of Black votes meaningless by packing roughly 62% of Black residents in the growing First District into another district that has been represented by a Black Democrat – Jim Clyburn – for the last 30 years, according to the court’s ruling.

In recent years, both parties have weaponized partisan gerrymandering, although Republicans have historically been the primary beneficiaries, and have used the tactic to greater effect since the last round of redistricting in 2010, Reuters reported in February 2022.

Democrats have engaged in partisan gerrymandering in Illinois and New Mexico, for example, according to a September 2022 report in the New York Times.

Still, a number of political analysts have concluded that Republicans wouldn’t have won the House without gerrymandering Tennessee, Texas, Georgia and Florida, according to a Jan. 6 report in The Cook Political Report and a December 2022 analysis by poll-tracking website FiveThirtyEight.

Moreover, besides South Carolina, courts in recent years have found that Republicans went beyond partisanship and engaged in racist election manipulation in Florida, in Alabama, in North Carolina and Louisiana, for example.

In a number of cases, the Supreme Court’s recent rulings meant that maps found discriminatory by courts were used in state elections, further entrenching an unfairly obtained and racially exclusionary electoral advantage for conservatives.

The South Carolina ruling is just the latest example of how the high court has paved the way for a continuing siege on voting rights.