Texas, you're starting to make my head hurt today. In still more developments out of the courts, the United States Supreme Court has agreed to consider the principle of "one person, one vote" outlined in the Constitution for purposes of drawing Congressional districts.

The Supreme Court agreed on Tuesday to hear a case that will answer a long-contested question about a bedrock principle of the American political system: the meaning of “one person one vote.”

The court’s ruling, expected in 2016, could be immensely consequential. Should the court agree with the two Texas voters who brought the case, its ruling would shift political power from cities to rural areas, a move that would benefit Republicans.

The court has never resolved whether voting districts should have the same number of people, or the same number of eligible voters. Counting all people amplifies the voting power of places with large numbers of residents who cannot vote legally, including immigrants who are here legally but are not citizens, illegal immigrants, children and prisoners. Those places tend to be urban and to vote Democratic.

A ruling that districts must be based on equal numbers of voters would move political power away from cities, with their many immigrants and children, and toward older and more homogeneous rural areas.

I'll bet you can't guess who will get screwed if conservatives win the day? That's right. Most of us.

Such a decision, said Richard H. Pildes, a law professor at New York University, “would be most significant in border states, like California, Texas, Arizona and Nevada, that have the largest proportions of noncitizens.”

Yes, kids. It's screw-the-country-to punish-immigrants day at the Supreme Court. The fact that they agreed to hear it at all is concerning, but the consequences of turning precedent on its head would be terrible.

The new case, Evenwel v. Abbott, No. 14-940, concerns state and local voting districts. But “the logic of the decision in Evenwel will likely carry over to congressional redistricting,” said Richard L. Hasen, a law professor at the University of California, Irvine.

The case, a challenge to voting districts for the Texas Senate, was brought by two voters, Sue Evenwel and Edward Pfenninger. They are represented by the Project on Fair Representation, the small conservative advocacy group that successfully mounted the earlier challenge to the Voting Rights Act. It is also behind a pending challenge to affirmative action in admissions at the University of Texas at Austin.

In the new case, the challengers said their voting power had been diluted. “There are voters or potential voters in Texas whose Senate votes are worth approximately one and one-half times that of appellants,” their brief said.

In a statement issued after the Supreme Court accepted their case, Ms. Evenwel and Mr. Pfenninger said they “hoped that the outcome of our lawsuit will compel Texas to equalize the number of eligible voters in each district.”

Professor Hasen said their lawsuit was in tension with some conservative principles.

“It is highly ironic that conservatives, who usually support respect for precedents and states’ rights, are bringing a case that if successful will not only upset decades-old case law but also restrict the kind of representation states may choose,” he said.

Not ironic, Professor Hasen. Just the usual effort to disenfranchise voters and empower billionaires.