The Supreme Court unanimously ruled against challengers seeking to change the long-held interpretation of the principle of one person, one vote. Siding with a lower court, the 8-member high court held that total population could be used to draw electoral districts.

The decision for the case, Evenwel v. Abbott, was written by Justice Ruth Bader Ginsburg. Justice Samuel Alito and Justice Clarence Thomas each filed concurring opinions.

“Appellants have shown no reason for the Court to disturb this longstanding use of total population,” Ginsburg wrote.

The challengers had argued the use of total population — which includes non-citizens, but also children and disenfranchise prisoners — to draw districts was unconstitutional because it diluted the political power of eligible voters. Civil rights advocates argued that the lawsuit was an attempt to increase the political power of white suburban and rural voters, who tend to vote Republican, at the cost of minority and urban communities, which have a larger share of non-eligible voters in their districts.

The lawsuit was spearheaded by Edward Blum, a conservative legal advocate who has also targeted the Voting Rights Act and college affirmative action policies through legal challenges. The plaintiffs were Texas voters objecting to the state’s Senate districting plan, who said their votes counted less than the votes in neighboring districts where there are a lower percentage of eligible voters.

In her majority opinion, Ginsburg said that the challengers had failed to show that the Texas districting plan was unconstitutional. She also said that the challengers did not present a convincing argument that districts should be drawn to have roughly equal number of voters, rather than total populations.

“For every sentence appellants quote from the Court’s opinions, one could respond with a line casting the one-person, one-vote guarantee in terms of equality of representation, not voter equality,” she wrote.

Her opinion dug into the history of how the 14th Amendment was written to argue its framers resisted specifically the idea of drawing districts based on eligible voters. Furthermore, she suggested that mandating that states draw districts based on eligible voters would be impractical.

“What constitutional history and our prior decisions strongly suggest, settled practice confirms,” she wrote. “Adopting voter-eligible apportionment as constitutional command would upset a well-functioning approach to districting that all 50 States and countless local jurisdictions have followed for decades, even centuries.

She added that the challengers “have shown no reason for the Court to disturb this longstanding use of total population. “

Thomas, who the challengers had hoped would be sympathetic to their claims, wrote that the Supreme Court had still left the issue very muddled over the history of its decisions in redistricting cases.

“Under these circumstances, the choice is best left for the people of the States to decide for themselves how they should apportion their legislature,” he said.

Alito, likewise, said that he agreed with the majority that a state should be permitted to use total population, but that the majority went too far in arguing the historical and constitutional contexts that supported using total population.

“It is impossible to draw any clear constitutional command from this complex history,” Alito wrote.

Read the decision below: