A unanimous Supreme Court ruled Monday that states can count everyone, not just eligible voters, in deciding how to draw electoral districts.
 
The justices turned back a challenge from Texas voters that could have dramatically altered political district boundaries and disproportionately affected the nation's growing Latino population.

The court ruled that Texas' challenged state Senate districting map, using total population, complied with the principle of "one person, one vote," the requirement laid out by the Supreme Court in 1964 that political districts be roughly equal in population.

The issue, though, was what population to consider: everyone or just eligible voters.

The challengers said the districts had vastly different numbers when looking at eligible voters, in violation of the Constitution.

"Jurisdictions, we hold, may design state and local legislative districts with equal total populations; they are not obliged to equalize voter populations," Justice Ruth Bader Ginsburg said, summarizing her opinion for the court.