Last Tuesday the Supreme Court issued a short, per curiam opinion in Tennant v. Jefferson County, which rejected a challenge to West Virginia’s recently redrawn Congressional districts. The one-person-one-vote doctrine requires that legislative districts be close to the same size (so that each person’s vote is approximately the same share of the total), and there was a 0.79% difference between the smallest and largest district in West Virginia. The Court concluded that under the circumstances, however, that difference was permissible.
In particular, the Court concluded that it was legitimate to deviate from equal-sized districts, among other reasons, in order to ensure that districts lines could track county lines. That’s notable because one of the potential problems with the one-person-one-vote rule is that it enables (or even encourages) gerrymandering. State law often requires districts to follow county lines, which makes it harder to manipulate the exact boundaries of a district for political reasons. But since county populations will almost never generate perfectly-equal districts, a perfect equality rule allows (and requires) redistricting states to ignore their own anti-gerrymandering rules. By holding that perfect equality can be subordinated to the county-line principle, the Court creates more room for state anti-gerrymandering rules.
This point is driven home by another part of the opinion, which rejected the claim that technological advances (like the use of computers in redistricting) made the range of acceptable variation smaller. The reason increased technology doesn’t shrink the range of acceptable variation is that the Court cares about why the state plan has the variations, not just whether they can be avoided.
To be sure, it is too soon to tell whether this is the start of a bigger change to the one-person-one-vote principle, or just a minor tweak in a fact-specific situation. A previous decision, Karcher v. Daggett, had suggested that variations could sometimes be justified, but it was vague about when and how much (and rejected them in that case). Two big questions going forward will be how big of a variance the Court is willing to permit in preserving values likes county lines, and whether Tennant is part of a bigger trend of federalism in federal election law. Stay tuned.