A recent Daily Journal explained why the so-called “efficiency gap” analysis falls short of its goal of differentiating acceptable partisan election mapmaking from unconstitutional gerrymandering.

The latest issue of Commentary magazine features Syracuse law professor Tara Helfman‘s take on the same topic.

The Wisconsin plaintiffs claimed to have found the holy grail of political law: a “judicially discernible and manageable standard” against which to assess the constitutionality of a redistricting plan. The grail, they claimed, was a mathematical formula known as the “efficiency gap.” The efficiency gap (EG) divides the difference between the respective parties’ wasted votes by the total number of votes cast. (A “wasted vote” is a vote cast for a losing candidate or a winning candidate in excess of a bare majority.) Applying the efficiency gap to Act 43’s redistricting plan, the Court found that the inefficiency among districts evidenced the plan’s unconstitutional partisan effect.

Now, the Constitution enumerates many rights, but the right to an equal number of wasted votes is not among them. By adopting the “efficiency gap” as the golden mean of American politics, the district court almost certainly overstepped the constitutional boundaries established by the separation-of-powers doctrine. The late Justice Antonin Scalia memorably explained the doctrine’s relevance to political law in Veith v. Jubelirer, a case in which Pennsylvania Democrats challenged a veritable bestiary of purported gerrymanders that included the notorious District 6, a “dragon descending on Philadelphia from the west.” Scalia noted that

the judicial power created by Article III, §1 of the Constitution is not whatever judges choose to do?.?.?.?or even whatever Congress chooses to assign them.?.?.?.?It is the power to act in the manner traditional for English and American courts. One of the most obvious limitations imposed by that requirement is that judicial action must be governed by standard, by rule. Laws promulgated by the Legislative Branch can be inconsistent, illogical, and ad hoc; law pronounced by the courts must be principled, rational, and based upon reasoned distinctions.

Short of judicial preference, it is not clear why the “efficiency gap” is more principled, rational, and reasoned than other possible approaches to political apportionment. Congress may have the power to enact the efficiency gap into law under its Article I powers, but the courts do not have the power to declare it the law by judicial fiat.