THE SUPREME COURT rejects about 99% of the 7,000 to 8,000 petitions that reach it each year. But when it comes to cases involving reapportionment—challenges to how states draw lines for congressional or state legislative elections—the justices can’t be quite so choosy. Congress has chipped away at the cases subject to mandatory review by the Supreme Court, but it has kept it for redistricting cases where an election looms and time is of the essence. If skewed electoral maps may need to be redrawn, a special three-judge federal court is convened to hear the case; an appeal goes right to the Supreme Court, bypassing America’s 13 circuit courts.

This quirk of Supreme Court procedure explains why the justices have now agreed to hear four gerrymandering cases this term, including two added on January 12th. These recurring matters may be their least-favourite to resolve. In 2016, Justice Stephen Breyer told lawyers in a racial-gerrymandering dispute that he had hoped his majority opinion in a similar 2015 case “would end these cases in this court”. But Alabama Legislative Black Caucus v Alabama “certainly doesn’t seem to have” done so, Justice Breyer rued then. And, apparently, 2017 rulings in Bethune-Hill v Virginia State Board of Elections and Cooper v Harris haven’t done so either.

The latest disputes over electoral lines come from Texas and are, in election-law expert Rick Hasen’s words, “crazy with details”. Both cases ask whether race improperly influenced the state legislature’s map-making and both—to make things more confusing—are styled Abbott v Perez. (Greg Abbott is the governor of Texas; Shannon Perez is an Hispanic voter who lives in Bexar County.) But the two cases address two different maps—one for congressional districts, another for state legislative districts—and involve slightly different claims of racial unfairness.

Last August, a ruling by a three-judge panel in San Antonio held that two of Texas’s 36 congressional districts were drawn to minimise minority voting power, in violation of both the Voting Rights Act and the Fourteenth Amendment guarantee of the “equal protection of the laws”. In District 27, covering Corpus Christi, Texas’s 8th-largest city, Hispanics were “intentionally deprived of their opportunity to elect a candidate of their choice”. District 35, meanwhile—a skinny, long district resembling the nation of Chilé—showed signs of an “impermissible racial gerrymander", line-drawing based predominantly on racial considerations. Texas countered that its gerrymander was merely partisan, not racial, but the court roundly disagreed.

Nine days later, on August 24th, the same federal court found that several state legislative districts—on a map to elect lawmakers to the Texas House of Representatives—did not pass legal muster. Two districts in Dallas were found to be “packed” with Hispanic voters, decreasing Hispanic voting power in nearby areas. Other districts were specifically designed to “crack” Hispanic voter strength by parcelling minority voters into a number of districts where their voice in each would be faint. The Texas legislature, the court concluded, aimed “to ensure Anglo control” of the vote in these parts of the state.

The remedy to these discriminatory maps, the court held, was a new set of maps to be drawn by the legislature in a special session last autumn. But Texas quickly asked the Supreme Court to temporarily block those orders, and, by a 5-4 vote, it did. Now the cases will get a full consolidated hearing on the merits, probably in late April, as the justices wind down their 2017-2018 argument schedule. With these additions to the Supreme Court’s docket, late June will probably bring a trio of highly anticipated decisions on the contours of gerrymandering in America.

The justices have already heard Gill v Whitford, a challenge to a partisan Republican-drawn gerrymander in Wisconsin, and they will soon consider a partisan map favouring Democrats in Maryland in Benisek v Lamone. Those cases mark the justices’ first opportunities in over a decade to decide whether maps drawn to marginalise voters from one party violate the constitution—and will help resolve an especially brazen Republican effort in North Carolina to rope Democrats out of contention for congressional races. Together with the race questions in Abbott v Perez, the justices have their hands full clarifying the statutory and constitutional limits on electoral-map cartography. But it’s a safe bet that whatever the court says this spring, it won’t be the justices’ last word on the subject—much to their chagrin.