NYT:

The court said unanimously that the state could take into account all of its 27 million residents when it carves its territory into voting districts for the State Senate, regardless of whether they can vote in elections. It was a setback for conservatives who want to limit that redistricting population to eligible voters, and a resounding affirmation of the one-person-one-vote principle that has governed most redistricting nationwide for decades.

But it was probably not the final word because the court was silent on whether any other population formula could be used to draw new voting districts. And within hours, advocates on both sides of the issue indicated that Texas or another conservative-dominated state was bound to do just that, probably after the 2020 census triggers a new round of redistricting nationwide.

“This has been an issue that has bubbled up in the courts and in the realm of social science pretty consistently,” said Edward Blum, the president of the Project on Fair Representation, the conservative advocacy group that brought the lawsuit. He said the group would urge political officials to abandon the one-person-one-vote formula for a more limited guideline, something that almost certainly would lead to a second court battle. And the state of Texas, the defendant in the group’s lawsuit, indicated in court filings that it would prefer to have that option.

“The big case isn’t this case, but the next case,” said Daniel P. Tokaji, a professor at Ohio State’s Mortiz College of Law and an authority on elections law.