A federal judge late Friday voided a key provision of the state's system of publicly financed elections.
Judge Roslyn Silver said it is unconstitutional for the government to provide matching funds to candidates who campaign with state dollars when their privately financed foes spend more.
She said the system can be "manipulated" in ways that financially harm those who decline to take government dollars.
But Silver refused a request by the Goldwater Institute, which is representing several candidates using private donations, to immediately halt the match. The judge said doing so now - just days before Tuesday's primary - could throw the election into disarray.
Instead she told the lawyers for those challenging the law and those representing the state to be in her court Wednesday, the day after the election, when she will hear evidence on whether to bar matching funds for the November general election.
Friday's ruling is a key victory for privately financed candidates who contend the system is stacked against them.
The law, approved by voters in 1998, allows - but does not require - candidates for statewide and legislative office to get public dollars for their campaigns if they promise not to take any other outside dollars above what they are allocated.
The provision at issue says if a privately funded foe spends more than that allocation, the person running with public funds - called a "participating candidate" - gets a dollar-for-dollar match, up to three times the original amount. So a candidate for the Legislature in a contested primary, who would normally get $19,362, can end up with more than $58,000.
Silver said campaign finance laws have been found constitutional when the government shows they serve a legitimate public purpose. And she said that, on the surface, this law meets that goal by dissuading candidates from relying on private dollars and, by extension, discouraging corruption.
But the judge noted the law also provides matching funds when anyone else spends money on behalf of the privately financed candidate, even without permission. That, she said, "opens up new avenues for possible corruption."
For example, Silver said, a political action committee can surreptitiously help a publicly funded candidate by running "ineffective, unwished-for advertising" for the privately funded foe. "That generates funds for the participating candidate to use at her discretion," the judge said.