The U.S. Supreme Court on Thursday delivered a ruling that protects Black voting power, shocking court watchers who feared that the court’s conservative majority would use the case to further weaken the Voting Rights Act of 1965.

In its 5-4 Allen v. Milligan decision, the bench affirmed a lower court ruling that said that Alabama’s newly enacted congressional map likely violates Section 2 of the VRA — a crowning achievement of the midcentury Civil Rights Movement — and its protection against racial vote dilution. While Black Alabamians make up around 27% of the state’s voting-age population, they hold a majority in only one of the seven districts under the map in question.

Section 2 asserts that marginalized communities must have an equal opportunity “to participate in the political process and to elect representatives of their choice.” The lower court judges told Alabama lawmakers that they must create a second majority-Black district, and the Supreme Court upheld that ruling.

“This decision is a crucial win against the continued onslaught of attacks on voting rights,” Deuel Ross, the deputy director of litigation at the NAACP Legal Defense Fund, said in a statement.

“Alabama attempted to rewrite federal law by saying race could not be considered in the redistricting process, even when necessary to remedy racial discrimination,” added Ross, who argued the case before the court last year. “Because of the state’s sordid and well-documented pattern of persisting racial discrimination, race must be considered to ensure communities of color are not boxed out of the electoral process.”

Thursday’s decision is surprising in part because Republican-appointed Chief Justice John Roberts joined the court’s three liberal justices in upholding Section 2, even though he has a decades-long history of campaigning against the VRA. Justice Brett Kavanaugh, who was appointed by former President Donald Trump, also joined the liberal members, who include Justices Sonia Sotomayor, Elena Kagan, and Ketanji Brown Jackson.

Evan Milligan, a lead plaintiff in the case and the executive director of the nonpartisan civic engagement network Alabama Forward, described the court’s decision as a “victory for BIPOC communities and pro-democracy advocates across the country.”

“We are grateful that the Supreme Court upheld what we knew to be true: that everyone deserves to have their vote matter and their voice heard,” he said in a statement.

This win shouldn’t overshadow how the VRA has been defanged in recent years. In 2013, the high court gutted Section 5’s mandate that states with histories of discrimination against Black voters get federal approval before changing voting and election procedures.

Melissa Murray, a law professor at New York University, offered a sobering analysis of Thursday’s decision. While the ruling is “a victory that maintains the status quo for Section 2,” she explained on Twitter, it’s also “cold comfort when one considers the way this court through its decisions has actively distorted the electoral landscape and made true representative government more elusive.”

Still, Thursday’s decision is nothing to take lightly. As Milligan told Worldacad just earlier this week, the case was about giving Black voters greater agency in confronting various systemic inequalities.

“Having an additional district would allow people to have another representative who’s sympathetic to the region [the rural and impoverished ‘Black Belt’ region] as well as to the concerns of folks here,” he said. “And that congressperson would hopefully bring in resources and create a sense of urgency around community needs.”

This story has been updated.

Brandon Tensley is Worldacad's national politics reporter.