In a surprise move, two conservative Supreme Court justices sided with the liberal minority in a 5-4 decision striking down the map.
The majority sided with a District Court panel in opposing the maps that appeared designed to dilute the power of Black voters by dividing them into districts where white voters dominate.
"The District Court concluded that plaintiffs had carried their burden at the totality of circumstances stage given the racial polarization of elections in Alabama, where 'Black Alabamians enjoy virtually zero success in statewide elections' and where 'Alabama’s extensive history of repugnant racial and voting-related discrimination is undeniable and well documented,'" Chief Justice John Roberts said, writing for the majority in a court opinion.
"The [Supreme] Court sees no reason to disturb the District Court’s careful factual findings."
The Supreme Court affirmed the District Court's finding that plaintiffs demonstrated a reasonable likelihood of success on their claim that the Alabama law violates Section 2 of the Voting Rights Act of 1965.
The ruling means that the map of seven congressional districts, which skew heavily in favor of Republicans, must be redrawn.
US Attorney General Merrick Garland applauded the decision as a rejection of efforts to erode fundamental voting rights.
"All eligible voters must be able to exercise their constitutional right to vote free from discrimination based on their race," Garland said in a statement.
Alabama Attorney General Steve Marshall said that while the majority’s decision is disappointing, "this case is not over."