Yesterday’s Supreme Court opinion in Davenport arose out of no split among state courts or federal circuits. As the Washington Post notes, the law itself was unique to Washington, and hardly even a law there anymore: “Though no other states have adopted laws similar to Washington’s, yesterday’s ruling confirms that they have a right to do so. But its immediate practical impact in Washington state was limited by the legislature’s adoption of a new law on May 10 that stipulates union political spending is not considered to come from agency fees.”
So why did the Supreme Court take the case? Sometimes an opinion is so wrongheaded that the Court is willing to engage in correcting errors, lest bad rulings get picked up by other courts and get out of control. (UPDATE: A knowledgeable reader writes to add that the error correction point is especially strong given that the Court could well have dismissed this case on mootness grounds.) Error correction is the primary reason I have advocated that the Court take Crawford, the Indiana voter id case, and the argument is much more compelling than in Davenport:

1. Error correction. Judge Posner’s opinion is at best sloppy, and at worst pernicious, in its treatment of empirical evidence and how it bears on this controversy (even under a relatively low standard of review). Given Judge Posner’s reputation, this opinion is likely to have ill effects far beyond the Seventh Circuit. Taking the case will also give the Court a chance to correct its own errors as to the proper balancing in voter id cases that it set forth in Purcell v. Gonzalez. (I make both of these arguments in great detail here so I won’t rehash them now.) Though error correction is not a usual reason for the Court to take a case, voter id controversies are going to continue to attract great attention and controversy as they are passed by legislatures and decided by the courts. The Court can correct error and give guidance on the proper balancing in these cases.