A major effort by Montana, campaign finance reform groups and more than 20 states to persuade the U.S. Supreme Court to reconsider its widely criticized Citizens United decision failed on Monday.

In a 5-4, two-paragraph, unsigned opinion, the justices reversed a ruling by the Montana Supreme Court last year that upheld that state’s century-old ban on corporate spending in state elections.

“In Citizens United v. Federal Election Commission, this Court struck down a similar federal law, holding that `political speech does not lose First amendment protection simply because its source is a corporation,’” wrote the majority. “The question presented in this case is whether the holding of Citizens United applies to the Montana state law. There can be no serious doubt that it does.”

Justice Stephen Breyer, joined by justices Ruth Bader Ginsburg, Sonia Sotomayor and Elena Kagan, dissented. Breyer, Ginsburg and Sotomayor had dissented as well in the 2010 Citizens United ruling. Kagan, as solicitor general, unsuccessfully represented the federal government in the Citizens United case.

Even if he were to accept the Citizens United decision, Breyer wrote on Monday, “this Court’s legal conclusion should not bar the Montana Supreme Court’s finding, made on the record before it, that independent expenditures by corporations did in fact lead to corruption or the appearance of corruption in Montana. Thus, Montana’s experience, like considerable experience elsewhere since the Court’s decision in Citizens United, casts grave doubt on the Court’s supposition that independent expenditures do not corrupt or appear to do so.”

The majority’s reversal came in American Tradition Partnership v. Bullock. American Tradition and two Montana companies had asked the justices to reverse the state supreme court. Montana Attorney General Steve Bullock had asked the justices to affirm or to grant American Tradition’s petition for review and to schedule the case for briefing and argument.

“One hundred years ago, Montanans passed an initiative to protect democracy, to give everyday people a voice that would no longer be silenced by a sea of corporate money,” said Bullock in a statement. “Despite this disappointing decision, the last word has not been spoken on the issue of how we preserve a viable democracy in which everyday people have a meaningful voice. History will show that it was Montanans and the Montana Supreme Court that understood the heart of this issue and stood on the side of ‘We the people.’”

The challenge to the Montana law and the subsequent petition by American Tradition was brought by James Bopp Jr. of the Bopp Law Firm in Terre Haute, Ind. Bopp also represented Citizens United when it sought review in the U.S. Supreme Court.

Bopp said on Monday that the justices’ action in the Montana case closes the door on arguments that a state’s unique history or facts can be used to overturn Citizens United.

“This is an excellent result,” said Bopp. “The Court has shut the door on a multi-million dollar effort to lobby and even intimidate the Court into reconsidering Citizens United. Groups of persons of average means will still be able to pool their resources to effectively participate in our democratic process.”

Election law scholar Richard Hasen of the University of California-Irvine School of Law suggested on his Election Law Blog that if the court had agreed to take up the Montana case, the outcome may have been worse for campaign finance reformers than Citizens United. For example, the ban on direct contributions by corporations may have been struck down.

“The best way to win before the Roberts Court if you are a campaign reformer (aside from on disclosure issues) is not to play,” wrote Hasen. He also noted that Kagan’s position as a justice is now clear: She has adopted the dissenting view in Citizens United. That means there are now four solid votes to overturn the decision, he added.

Campaign finance reform groups and good government organizations, such as Common Cause, reacted to the Montana decision by calling for a constitutional amendment to reverse Citizens United and for federal legislation to strengthen disclosure of campaign expenditures.

Marcia Coyle can be contacted at mcoyle@alm.com.