On June 25, the U.S. Supreme Court summarily struck down Montana’s law that makes it illegal for corporations to make independent expenditures for or against candidates for state and local office. The case is American Tradition Partnership v Bullock, 11-1179. Here is the very brief opinion. The vote was 5-4.
On December 30, 2011, the Montana Supreme Court had voted to uphold the Montana law by a vote of 5-2. The Montana Supreme Court decision seemed to defy the U.S. Supreme Court 2010 decision in Citizens United v FEC. That is why the U.S. Supreme Court majority felt there was no need to set the case for oral argument and full briefing. The 4-person minority on the U.S. Supreme Court would have simply refused to hear the Montana case, which would have left the Montana law in place.