In what is becoming a comically pro-corporation series of rulings, the U.S. Supreme Court on Monday invalidated Arizona’s campaign finance law that was intended to buttress insurgent candidacies with public funds so as to level the playing field in local elections:

Arizona said its public-financing system promoted free speech by giving candidates the opportunity to run for office without depending on private political donors. But the law’s challengers—five conservative politicians and two political action committees—said the law stifled free speech. They argued that, when they raised and spent money to promote their messages, their speech was punished because it triggered government subsidies to their rivals.

The Supreme Court’s conservative majority agreed with the challengers in a 5-4 ruling.

Chief Justice John Roberts wrote the majority opinion, the latest in a series of rulings where the court’s conservative majority has overturned efforts to increase regulation of campaign funding.

“Laws like Arizona’s…that inhibit robust and wide-open political debate without sufficient justification cannot stand,” he wrote, joined by Justices Antonin Scalia, Anthony Kennedy, Clarence Thomas and Samuel Alito.

The newest justice, Elena Kagan, wrote the dissent, joined by Justices Ruth Bader Ginsburg, Stephen Breyer and Sonia Sotomayor. She argued that states had legitimately sought to keep elections clean by keeping “massive pools of private money from corrupting our political system.”

In this case, a voter-imposed control on the influence of money in politics was directly contradicted by the Supreme Court, which apparently felt the need to do justice on behalf of the oppressed–in this case, wealthy candidates and Political Action Committees.

In a conference call with reporters, Monica Youn of the Brennan Center for Justice, which helped defend the law before the Supreme Court, said that the “very charismatic, conservative vision of deregulation of campaign finance” won the day.

She pointed to the Court having acknowledged the legitimacy of campaign finance rules in general as a bright spot, and praised Obama appointee Elena Kagan as “staking her claim to be the reform champion” among the justices. [The Wall Street Journal]