The court's emergency orders throws a wrench into the state's campaigns two months before its primary elections. It is the latest sign the high court's conservative bloc is skeptical of legal rules to limit election spending or to equalize the spending between wealthy and not-so-wealthy candidates.

Two years ago, the court in a 5-4 decision intervened on a behalf of a wealthy candidate for Congress from upstate New York and struck down the so-called "Millionaire's Amendment." That measure, part of the McCain-Feingold Act, allowed a candidate to raise more money through larger donations if his opponent was spending lavishly. Justice Samuel A. Alito Jr. called it a "drag" on the free-speech rights of the millionaire candidate because he was penalized for spending more on his race.

That ruling, in turn, fueled a 1st Amendment challenge to Arizona's Clean Elections Law, which was approved by its voters in 1998. The measure was designed to combat corruption in the state legislature. It providing public funds for candidates who agreed to abide by limits on spending and fund-raising.