Supreme Court Should Draw a Line on Gerrymanders

(Bloomberg View) -- What former Supreme Court Justice Potter Stewart once said about pornography is also true of gerrymandering: You may not be able to define it, but you know it when you see it. This week the justices will be presented with an opportunity to define and thereby limit gerrymandering, the practice of drawing election districts for partisan advantage. They should seize it.

The case concerns the map approved in 2011 for the Wisconsin Assembly. Last year, a three-judge district court concluded that state Republicans had so egregiously contorted the state's political map that it required a court-ordered remedy. The ruling was unusual because while courts have invalidated maps designed to exploit racial advantages, they have generally left alone gerrymanders designed for partisan advantage.

Such reluctance is understandable. Gerrymanders have been part of U.S. political life since at least 1812, when the term arose to describe the beastly shape of a district on a Massachusetts map. The courts have long been wary, justifiably, of too much involvement in purely political questions.

Wisconsin officials defending their map -- and the right of Republican legislators to draw it as they see fit -- say it is consistent with "traditional redistricting principles" and a centuries-old status quo. That is both correct and beside the point.

The Wisconsin map, drawn with a digital precision unavailable in past centuries, yielded a skewed portrait of the electorate. Two elections occurred under the plan before a suit was filed. In the 2012 election, Republicans won 48.6 percent of the statewide vote yet claimed 60 of 99 seats in the Assembly. In 2014, Republicans won 52 percent of the vote and 63 seats. When political maps translate these margins into decisive imbalances of power, something in the democratic chemistry is amiss.

The plaintiffs not only asked the court to throw out these maps, they also proposed what the courts have previously lacked: a standard for judging whether any such maps deny voters their constitutional right of equal protection under the law.

Under a proposed “efficiency gap,” if a political party “wastes” too many of its votes due to the way districts are drawn, a map is invalid. The proposal is a direct response to Justice Anthony Kennedy, who in 2004 said he would be open to declaring partisan gerrymanders unconstitutional if a workable standard for identifying them could be devised.

The efficiency gap, which is easier to understand than to describe, is not a perfect solution to the problem of partisan gerrymanders. But it's a pretty good one -- equally effective at identifying whichever party is being intentionally disadvantaged. It would bolster the complaints of Illinois Republicans as surely as those of Wisconsin Democrats.

Kennedy now has the workable standard he sought. When the case comes before the court, he and his colleagues should be ready to apply it. Allowing blatant partisan gerrymanders to stand, as a group of Republican state officials argue in a brief filed with the court, would be “devastating for our democracy.”

--Editors: Francis Wilkinson, Michael Newman.

To contact the senior editor responsible for Bloomberg View's editorials: David Shipley at davidshipley@bloomberg.net.

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