WASHINGTON — The Supreme Court ruled unanimously on Monday that states may use total population in making redistricting decisions — and need not use voting population, as some conservatives had sought.

Sue Evenwel and Edward Pfenninger had challenged Texas' state legislative redistricting, arguing the state had to include consideration of the eligible voting population in redrawing its legislative borders.

The challenge could have upended state redistricting decisions across the nation — all of which use total population currently in making redistricting decisions. Critics raised questions about how a decision requiring consideration of eligible voters in redistricting would affect representation of children below voting age and, thus, families, as well as prison populations and immigrants not eligible to vote.

A victory for Evenwel and Pfenninger could have led to states across the nation being forced to reconfigure their state legislative maps to ensure that new “one person, one vote” voter-based metrics still would result in maps that treat voters equally across districts.



The high court, analyzing its history of "one person, one vote" cases, rejected that request. "As history, precedent, and practice demonstrate, it is plainly permissible" to use total population for state redistricting, Justice Ruth Bader Ginsburg wrote for the court.

Although Justices Clarence Thomas and Samuel Alito joined the court's decision allowing total population to be used, they did not join Ginsburg's opinion for the court.

Alito, for his part, apparently believed the court's opinion went too far toward suggesting that total population was required to be used, as opposed to only ruling that states could decide to use total population. In an opinion concurring only in the court's judgment, Alito, joined by Thomas, criticized portions of the majority opinion that "suggest[]" historical evidence of a constitutional requirement for use of total population in redistricting.



Thomas, wrote separately as well, criticizing the court's history on the entire "one person, one vote" principle, writing "the majority has failed to provide a sound basis for the one-person, one-vote principle because no such basis exists." Nonetheless, he joined the court's judgment because he believed states have "significant leeway" in deciding how to handle redistricting decisions and that includes using total population.