Updated

The Supreme Court agreed Tuesday to hear an important case about whether states must count only those who are eligible to vote, rather than the total population, when drawing electoral districts for their legislatures.

The case from Texas could be significant for states with large immigrant populations, including Latinos who are children or not citizens. The state bases its electoral districts on a count of the total population, including non-citizens and those who aren't old enough to vote.

But those challenging that system argue that it violates the constitutional requirement of one person, one vote. They claim that taking account of total population can lead to vast differences in the number of voters in particular districts, along with corresponding differences in the power of those voters.

A ruling for the challengers would shift more power to rural areas and away from urban districts in which there are large populations of immigrants who are not eligible to vote because they are children or not citizens. Latinos have been the fasting growing segment of Texas' population and Latino children, in particular, have outpaced those of other groups, according to census data.

"And because urban areas are more Democratic, the ruling could help Republicans," said Richard Hasen, an expert on election law at the University of California-Irvine law school.

The Project on Fair Representation is funding the lawsuit filed by two Texas residents. The group opposes racial and ethnic classifications and has been behind Supreme Court challenges to affirmative action and the federal Voting Rights Act.

The court's 1964 ruling in Reynolds v. Sims established the one person, one vote principle and means that a state's legislative districts must have roughly the same number of people. But the court has never determined whether the state must count everyone or just eligible voters — or have some leeway to choose.

The case brought by Texas residents Sue Evenwel and Edwared Pfenniger highlights a mainly rural district northeast of Houston that has 584,000 eligible voters, while a neighboring urban district has 372,000 eligible voters.

The result is that voters in the urban district have more sway than their rural counterparts, said Edward Blum, president of the Project on Fair Representation. Several conservative groups also are supporting the Supreme Court challenge.

Then-Gov. Rick Perry, a Republican, signed the redistricting plan into law. The state urged the justices to reject the case because "multiple precedents from this court confirm that total population is a permissible" way to draw districts.

"It is ironic that you have conservatives going up against the state of Texas seeking to get the Supreme Court to take away more discretion from the states," Hasen said.

Back in 2001, Justice Clarence Thomas urged his colleagues to settle the issue. Thomas issued a rare dissent when the court chose not to hear a case from Houston. "We have never determined the relevant 'population' that states and localities must equally distribute among their districts," Thomas wrote.

The case, Evenwel v. Abbott, 14-940, will be argued in the fall.

Like us on Facebook

Follow us on Twitter & Instagram