The principle of “one person, one vote” sounds simple. But this week, the Supreme Court will hear a case that reveals how not-simple it really is, and how race lurks in the background of profound legal questions.

According to the Constitution, states determine how their state and local legislative districts are drawn. For more than a century, many were based on geography, which led some sparsely populated rural districts to have as much representation as cities.

That changed in 1964, when the Supreme Court ruled, in the case of Reynolds v. Sims, that the Equal Protection Clause of the Constitution required districts to be based on population, not geography. “Legislators represent people, not trees,” wrote Chief Justice Earl Warren. And the Constitution requires that “the vote of any citizen is approximately equal in weight to that of any other citizen in the state.” The principle of “one person, one vote” was born.

Well, wait a minute. Suppose only half the people in District A can vote, because the other half are non-citizens, or children, or felons. Meanwhile, in District B, almost everyone can vote. That means that the voters in District A get twice as much representation as the voters in District B. That seems unfair.

And that is what the plaintiffs in Evenwel v. Abbott are alleging. They say that “one person, one vote” should really mean “one voter, one vote,” and that districts should be drawn based on eligible voters, not total population. Otherwise, some votes count more than others.

The devil, though, is in the details.

First, says Nathaniel Persily, a law professor at Stanford who specializes in election-law issues, no one’s ever counted eligible voters in that way before. The Census counts population, and it’s used around the country. But if the court requires states to use eligible-voter data instead, then, Persily told The Daily Beast, “every city, county, and school board in the country would have to redraw its lines. It’s a 50-state disaster.”

Rejecting federalism and imposing a uniform federal standard is a highly un-conservative thing to do, of course. And yet the people pushing this case are far-right conservatives, led by serial litigation activist Ed Blum. What’s going on? What is this case really about?

The answer is what you might expect: race. Latinos, in particular.

Evenwel is a case out of Texas, where the Latino population is booming. That means that there are a lot of places like District A in cities with Latino immigrants, who may be in the country legally but who have not yet gained citizenship. Meanwhile, there are a lot of District Bs in the white suburbs. If the Supreme Court rules for Evenwel, those white suburbs would instantly gain even more power in the state legislature.

That explains the involvement of Blum, who, since losing an election of his own in 1992, has engineered Supreme Court cases against affirmative action and the Voting Rights Act (including the notorious Shelby County v. Holder decision that eviscerated the VRA in 2013) and who is funded by anonymous conservative donors whose identities are shielded by financial nondisclosure rules.

Ironically, notes Persily, the Texas legislature has hardly been friendly to non-citizens. “Look at the laws Texas has been putting out,” he told The Daily Beast. “Redistricting, which Latino groups are suing over. Voter ID, which Latino groups are suing over. This is not an area where the court has to get involved.”

But that’s today. Demographers have estimated that Latino votes could “turn Texas blue” within two decades, possibly within even one. Add in districts where those votes “count more” than white suburban ones, and you can see the Texas old boy network disappearing like beer at a barbecue.

Isn’t it unfair, though, that voters in districts with a lot of non-voters count more than others?

Well, consider the alternatives.

First, if the Supreme Court rules for Evenwel, it will be creating a constitutional right out of thin air. In fact, though the Constitution is silent on state representation; everywhere it talks about federal representation it uses the word “people,” which included non-voting women and non-voting slaves. It mandates a census of population, not voters.

Indeed, as Persily noted, the loathsome Three-Fifths Compromise, which counted slaves as three-fifths of white men, was all about representation in Congress. If slaves, who could not vote, weren’t counted, the Southern states would have had 30 percent fewer electoral votes for president, and 30 percent fewer seats in Congress. So a compromise was reached in which slaves were counted, but not fully counted.

True, that’s about federal, not state, representation. But it would be quite odd for the Constitution to require counting voters (not population) for states while remaining totally silent on the matter, and while requiring the exact opposite (population, not voters) for federal purposes.

Second, as Persily said, “there’s a lot of unfairness in the political system” and a change in the way districts are drawn would simply move the unfairness around. If the court rules for Evenwel, some districts would have hundreds of thousands of people in them, while others would have only tens of thousands. Surely, resources would be allocated as a result, thus favoring the districts with lots of voters, but fewer people—who, let’s remember, are already disproportionately white, rich, and powerful. That sounds unfair, too.

Finally, there are the jurisprudential consequences. Justice Roberts, as I’ve written before, is a judicial conservative more than a social conservative. Will he really vote to junk a system being used everywhere for decades, and to require states and localities to spend billions of dollars because of something the Constitution doesn’t actually say?

Moreover, this recourse to the courts is exactly the kind of end-run around legislatures that conservatives usually complain about. Blum and his ilk know what would happen if the Texas legislature decided to redistrict this way: There would be an outcry and a likely backlash. So they’re going to the courts instead, trying to void every state’s system of redistricting and impose a uniform standard across the country. Hardly conservative, but when the alternative is the “browning of America,” folks get desperate.

We’ll see how many Supreme Court justices agree with them.