I have written this oped for the Washington Post. It begins:

Sometimes the most important stuff in Supreme Court opinions is hidden in the footnotes. In Monday’s Supreme Court ruling striking down two North Carolina congressional districts as unconstitutionally influenced by race, the majority buried a doozy, a potentially powerful new tool to attack voting rights violations in the South and elsewhere….

This seems to be a much more realistic approach to the interrelated matters of race and party than the court’s earlier treatment of them as either-or propositions for purposes of assessing the legality of gerrymandering. Indeed, political scientists refer to places such as North Carolina as states with “conjoined polarization,” where racial and partisan categories overlap. In North Carolina, about 90 percent of black voters are Democrats; conversely, the overwhelming majority of whites are Republicans. When the Republican legislature passes a plan to limit Democratic voting power, it necessarily affects black voters.

Under this logic, legislators will no longer be able to hide behind claims of partisan motivation to protect themselves from racial gerrymandering claims. Kagan’s approach should allow voting rights plaintiffs to bring more successful racial gerrymandering claims.

And this approach has broader application — especially important given the Supreme Court’s landmark 2013 decision overturning key portions of the Voting Rights Act that had required states such as North Carolina to get federal approval before making new voting rules that could hurt minority voters: Last week, the Supreme Court declined to review a North Carolina case involving voter identification and other strict voting laws. The U.S. Court of Appeals for the 4th Circuit had also treated race and party as proxies for one another and said that a partisan-driven voting law also constituted intentional race discrimination.