The U.S. Supreme Court has blocked the Montana Supreme Court's decision in December upholding the state's century-old ban on corporate political spending.

The ruling Friday evening sets up a possible full-blown U.S. Supreme Court rematch over the 2010 Citizens United decision that allowed unlimited corporate campaign spending. It came in response to an application submitted last week by American Tradition Partnership, a conservative interest group that says it fights "the radical environmentalist agenda," and two companies, seeking to have Montana's ban struck down. A five-member majority of the U.S. Supreme Court in Citizens United declared that corporations' independent spending in elections does not corrupt -- or even appear to corrupt -- the political process.

The Montana Supreme Court held that the state's history of corrupting corporate influence in politics, as well as the relative ease with which corporations may currently make expenditures through political action committees, distinguish the state's Corrupt Practices Act from the provisions of the federal McCain-Feingold Act that the U.S. high court struck down in Citizens United.

American Tradition asked the court to treat its application the same as a petition asking to reverse the Montana Supreme Court without additional briefing or argument. The justices, however, stayed the case "pending the timely filing and disposition of a petition" for a merits determination. That means American Tradition now has to return to the court with a more complete request for the justices' review.

Justice Ruth Bader Ginsburg, joined by Justice Stephen Breyer, welcomed the opportunity for the court to revisit, and potentially reverse, Citizens United. "Montana's experience, and experience elsewhere since this court's decision" in Citizens United "make it exceedingly difficult to maintain that independent expenditures by corporations 'do not give rise to corruption or the appearance of corruption,'" Ginsburg wrote in a statement accompanying the stay order. "A petition for certiorari will give the court an opportunity to consider whether, in light of the huge sums currently deployed to buy candidates' allegiance, Citizens United should continue to hold sway."

Justices Ginsburg and Breyer joined Justice John Paul Stevens's 90-page dissent in Citizens United. Justice Sonia Sotomayor did as well, but she and Justice Elena Kagan -- Stevens's successor -- did not join Ginsburg's statement.

American Tradition now has until the end of March to formally ask for the court's review. If it fails to do so, the Montana Supreme Court decision stands.

Montana Attorney General Steve Bullock said in a statement:


"While I’m disappointed that for the first time in 100 years Montanans won’t be able to rely on our corporate spending ban to safeguard the integrity of our elections, I am encouraged that the Supreme Court will give this careful consideration and I look forward to continuing to fight for Montana in defending our century-old law.”

“For more than a century, anyone has been able to participate in Montana elections -- even out-of-state corporate executives. All we required is that they used their own money, not that of their stockholders, and they disclosed who they are.”

The case is American Tradition Partnership v. Bullock.

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