National: Just How Much Gerrymandering Is Unconstitutional? Wisconsin Plaintiffs Want the Supreme Court to Rule. | National Journal

Every dec­ade, when state le­gis­latures across the coun­try draw dis­tricts for them­selves and their con­gres­sion­al del­eg­a­tions, some law­makers vi­ol­ate voters’ con­sti­tu­tion­al rights by pack­ing mem­bers of the minor­ity party in­to as few dis­tricts as pos­sible. At least, that’s what the Su­preme Court has hin­ted at in past rul­ings, when it wrote that ex­treme par­tis­an ger­ry­man­der­ing can vi­ol­ate voters’ First and Four­teenth Amend­ment rights to free­dom of speech and due pro­cess. The prob­lem, the Court wrote in its 2006 League of United Lat­in Amer­ic­an Cit­izens v. Perry de­cision, is that it can’t strike down ger­ry­mandered maps without some sort of tool to de­term­ine ex­actly when dis­trict bound­ar­ies are skewed so drastic­ally that they dis­crim­in­ate based on voters’ party af­fil­i­ations. The wind­ing, snake-like dis­tricts of­ten used to il­lus­trate ger­ry­man­der­ing aren’t ne­ces­sar­ily signs of ill in­tent, and it’s of­ten ne­ces­sary to have some vari­ation in how po­lar­ized or com­pet­it­ive dis­tricts are. But the Wis­con­sin-based plaintiffs in a law­suit filed this sum­mer think that they have found the for­mula that the Court has been wait­ing for. And if they man­age to push their case to the high court and win, the law­suit’s con­sequences could ex­tend from Wis­con­sin across the en­tire na­tion.

In a new U.S. Dis­trict Court case, Whit­ford v. Nich­ol, the plaintiffs pro­pose judging ger­ry­man­der­ing via a concept called the “ef­fi­ciency gap,” based on an aca­dem­ic pa­per writ­ten in 2014 by polit­ic­al sci­ent­ists Nich­olas Stephan­o­poulos and Eric McGhee. The pro­pos­al is sur­pris­ingly simple for such an ar­cane sub­ject: Start by adding up each party’s “wasted” votes that don’t help them win a dis­trict. (If Party A wins 90 votes out of 100, 39 of its votes are wasted, since it only needs 51 for a ma­jor­ity. All 10 of Party B’s votes are also wasted in this scen­ario.) The dif­fer­ence between each party’s wasted votes, di­vided by the total num­ber of votes cast, is the “ef­fi­ciency gap.”

Across the Wis­con­sin State As­sembly, Stephan­o­poulos and McGhee found a 13-per­cent ef­fi­ciency gap in 2012 and 10-per­cent gap in 2014, both fa­vor­ing Re­pub­lic­ans. That trans­lates to Re­pub­lic­ans win­ning 13 per­cent more seats in 2012 and 10 per­cent more in 2014 than they would have un­der a map that treated mem­bers of both parties equally.

In Whit­ford, the plaintiffs use the ef­fi­ciency gap to il­lus­trate how steeply dis­ad­vant­aged Demo­crats are in the state. But be­cause Whit­ford is the first time that any plaintiffs have pro­posed this kind of test to meas­ure the ex­tremity of ger­ry­man­der­ing, the law­suit’s re­per­cus­sions could ex­tend far bey­ond Wis­con­sin.

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