New York Times editorial on yesterday’s Montana decision:

The court’s five conservative justices struck down a Montana law that prohibited corporate spending in elections — a law passed in 1912 not out of some theoretical concern about money corrupting elections but to put an end to actual influence-buying by copper barons.

State officials told the court that fighting corruption required them to maintain limits on corporate election spending. A series of friend-of-the-court briefs urged the justices to allow other states to impose similar laws, citing the out-of-control spending unleashed since 2010.