Racial gerrymandering has been declared unconstitutional because ace is a suspect classification under the equal protection clause. Any attempt to undermine representative strength leads to unequal protection. But party identification is not a suspect classification, so partisan gerrymandering is perfectly fine. Except that it - now - may violate the principle of "one person one vote" since the ability of the party in a legislature to minimize the power of the minority has been greatly enhanced by new technologies.
The courts are being presented with an argument that an "efficiency gap" can be used to determine if the votes of the minority party have been excessively lessened. Partisan gerrymandering can occur when greater numbers of one party are placed in a smaller number of districts, meaning that more of their votes are "wasted" than those of the other party.
For a quick review, click here: Why the Ruling Against Wisconsin’s Gerrymander Could Change Redistricting in America.
The courts have struck down race-based gerrymanders as a violation of equal protection—but until now, they have consistently held that nakedly partisan gerrymanders do not by themselves pose a resolvable constitutional problem. That’s because of a muddled Supreme Court decision in 2004 called Vieth v. Jubelirer. In Vieth, five justices agreed that partisan gerrymanders are likely unconstitutional. But Justice Kennedy refused to actually strike them down. Kennedy wrote that extreme gerrymanders may unconstitutionally burden the “representational rights of voters,” but that there was not yet any “manageable standard” by which to assess whether a gerrymander ran afoul of the Constitution. He hoped such a standard might “emerge in the future,” leaving the door open to a future challenge.
That standard appears to have emerged. In an opinion written by Judge Kenneth Ripple, a Reagan appointee, the federal district court concluded that Wisconsin’s gerrymander violated voters’ right to freedom of association and equal protection under the First and Fourteenth Amendments. The Constitution prohibits a redistricting scheme, Ripple wrote, when it is intended to impede the effectiveness of a citizen’s vote based on her political affiliation; does, in practice, dilute that vote; and cannot be justified on other legitimate grounds.
How can courts determine whether a gerrymander excessively dilutes votes? Simple, Ripple explained: They can use a mathematical formula called the efficiency gap. As the New York Times explains it: The formula divides the difference between the two parties’ “wasted votes”—votes beyond those needed by a winning side, and votes cast by a losing side—by the total number of votes cast. When both parties waste the same number of votes, the result is zero—an ideal solution. But as a winning party wastes fewer and fewer votes than its opponent, its score rises.
A fair redistricting scheme will create few wasted votes and thus an efficiency gap near zero. The more partisan the gerrymander, the higher the efficiency gap; a review of gerrymanders over the last four decades revealed that an efficiency gap of 7 percent will entrench the majority until new districts are drawn. The current Wisconsin gerrymander results in an efficiency gap of up to 13 percent.
- The Campaign Legal Center: Whitford v. Gill.
- Brennan Center for Justice: Whitford v. Gill.
- Modern Democracy: Today, I’m Thankful for: Whitford v. Gill.
- The New York Review of Books: American Democracy Betrayed.
- The decision from the U.S. District Court: Whitford v. Gill.