Pamela S. Karlan, a law professor at Stanford, said the court had done damage to itself by going further than it needed to.

“To my mind,” she said, “the court’s effort to appear apolitical was undercut by the decision of the per curiam majority to go beyond the minimalist rationale of the concurrence — that there are special considerations with respect to the presidency that counsel against having state courts enforcing Section 3 — that could have gotten Justices Sotomayor, Kagan and Jackson to sign on. And for what?”