The Supreme Court has never struck down an election map on the ground that it was drawn to make sure one political party would win an outsize number of seats. But it has left open the possibility that some kinds of political gamesmanship in redistricting may be too extreme.

The problem, Justice Anthony M. Kennedy wrote in a 2004 concurrence, is that no one has come up with “a workable standard” to decide when the political gerrymandering has crossed a constitutional line.

Finding such a standard has long been, as one judge put it, “the holy grail of election law jurisprudence.”

In the coming weeks, the Supreme Court will consider an appeal from a decision in Wisconsin that may have found that holy grail. The case, Gill v. Whitford, No. 16-1161, arrives at the court in the wake of a wave of Republican victories in state legislatures that allowed lawmakers to draw election maps favoring their party.

The case started when Republicans gained complete control of Wisconsin’s government in 2010 for the first time in more than 40 years. It was a redistricting year, and lawmakers promptly drew a map for the State Assembly that helped Republicans convert very close statewide vote totals into lopsided legislative majorities.

In 2012, Republicans won 48.6 percent of the statewide vote for Assembly candidates but captured 60 of the Assembly’s 99 seats. In 2014, 52 percent of the vote yielded 63 seats.

Last year, a divided three-judge Federal District Court panel ruled that Republicans had gone too far. The map, Judge Kenneth F. Ripple wrote for the majority, “was designed to make it more difficult for Democrats, compared to Republicans, to translate their votes into seats.”

The decision was the first from a federal court in more than 30 years to reject a voting map as partisan gerrymandering.

Most cases reach the Supreme Court by way of petitions seeking review, which the justices are free to deny. The Wisconsin case is different. Congress requires the Supreme Court to hear appeals in some areas of election law, and Wisconsin officials have filed such an appeal.

That means the Supreme Court is very likely to weigh in on the fate of political gerrymandering, probably during the…