PHOENIX — The U.S. Supreme Court derailed a key part of Arizona's campaign financing system on Tuesday, preventing the state from giving extra money to publicly funded candidates facing privately funded rivals and changing the election rules in the thick of primary season.
The court stopped Arizona from disbursing so-called matching funds at least until it decides whether to hear the opponents' full appeal.
As they await a final ruling that may not come until the fall or even later, candidates and their advisers are reworking their strategies, with publicly funded candidates having to compete with fewer dollars.
"This ruling is obviously going to have a direct impact on candidates' strategy," Arizona State University political science professor Patrick Kenney said. "They (the court) could have let that sit until that race is over."
The court's brief order may have the greatest impact on the GOP gubernatorial primary, in which Gov. Jan Brewer, who is running with public financing, is facing a challenge from Buz Mills, a millionaire businessman largely using his own money in his first bid for office.
Under Arizona's system, candidates who opt for public financing can get matching funds up to two times their base amount when they're outspent by privately funded rivals or targeted by independent groups' spending.
Critics say the funds chill free-speech rights of privately financed candidates and their contributors by inhibiting fundraising and spending.
State officials and advocates of public campaign finance systems saying the matching funds help combat contributions-for-favors corruption and encourage more people to run for office.
Lower courts that considered Arizona's matching funds split on their constitutionality.
In the governor's race, Brewer has received her $707,000 base allotment but stood to get $1.4 million in matching funds. That's because Mills has already spent roughly $2.3 million, mostly on television advertising for his largely self-funded campaign.
Blocking matching funds helps Mills and hurts Brewer and Martin, Kenney said. But Brewer still has the incumbent's advantage of name recognition that Mills must overcome, he said.
Mills, who earned his fortune building cell phone towers, said he didn't know how the ruling would affect his campaign or how much he'd end up spending. "We're in this to win this race ... whatever it takes to get there," he said.
Brewer said in a prepared statement that she was troubled by the Supreme Court's action, saying it changed the rules in the middle of the election. Her campaign spokesman Doug Cole said Brewer's basic allotment isn't enough to pay for substantial television advertising.
Cole said the campaign will have to rely more heavily on Internet videos and social media.
Republican State Treasurer Dean Martin, planning to file within days for public funding, insisted that he won't be hurt by the order. He said Brewer and he will have the same amount of money and that Mills hasn't gained traction despite his spending.
"Arizona will be able to have its first elections in 10 years without having the government place its thumb on the scales in favor of publicly financed candidates," said Bill Maurer, an Institute for Justice attorney helping represent opponents of matching funds.
Supporters argued that blocking matching funds disrupts campaigns already under way and will result in less free speech.
"It's going to result in much less speech, much less information in the marketplace of ideas," said Todd Lang, executive director of Arizona's public campaign finance system.
Nearly half of the state-office candidates who qualified to run in the primary were running with public funding. Candidates qualify by collecting $5 contributions from voters, the number depending on the office sought.
At least two other states, Connecticut and Maine, have similar provisions in their public campaign finance systems, but Tuesday's Supreme Court order only affects Arizona.
The Supreme Court issued another campaign finance-related ruling in January, when it upheld the First Amendment rights of corporations and labor unions to spend money on campaign ads.
Associated Press writers Mark Sherman and Jonathan J. Cooper contributed. Sherman contributed from Washington.