The U.S. Supreme Court has blocked a Montana Supeme Court ruling upholding the constitutionality of that state’s ban on independent expenditures by corporations in state and local political campaigns.

In a unanimous order issued late Friday afternoon (and posted here), the high court’s justices stayed the Montana court’s decision. The move clears the way for independent expenditures in Montana, at least until the U.S. Supreme Court takes final action in the case.

Critics of the Montana court’s 7-2 decision issued Dec. 30 said it flew directly in the face of the U.S. Supreme Court’s Citizens United ruling in 2010 that struck down a law banning such spending in federal elections. However, the Montana court’s majority said the state’s unique history made the state ban constitutional.

Two U.S. Supreme Court Justices, Ruth Bader Ginsburg and Stephen Breyer, used the order Friday to call attention to the proliferation of Super PACs in the presidential race and to suggest that those funding such groups are eager to hold sway over the candidates.

‘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 […]