This is some of the early evidence on the effects of a state-level experiment in a type of campaign finance overhaul known to experts as "full public financing" and to supporters as "clean elections" that took effect in Maine, Vermont and Arizona this election.

The concept calls for replacing private campaign money with public money, presumably freeing candidates from potentially corrupting obligations to special interests. It offers candidates this deal: If, after an initial spurt of gathering small donations to qualify, they renounce all fund-raising, they will get enough public money for a modest campaign budget.

The idea has critics. Some say it is wrong to spend taxpayer money on campaigns; others say free campaign spending equals free expression. Court challenges were mounted in all three states, but the laws for the most part survived. Oregon and Missouri rejected "full public financing" ballot initiatives on Nov. 7.

Yet the idea clearly has legs on the state level. Massachusetts is slated to put its public financing law into effect next year, and efforts are expected in several state legislatures, from Connecticut to Minnesota to New Mexico, to pass such laws.

What has long been lacking in the debate over full public financing is empirical evidence of its effect on an election, until now. While no one is saying that public financing was the only factor in the Arizona State Senate upset or the Vermont Green Party's relative success, no one is denying it had an effect.

Jay Blanchard, the publicly financed Arizona Democrat who beat the departing speaker of the House, Jeff Groscost, for the Senate seat, told a forum on public financing here this week that he knew he could not have won if Mr. Groscost had not been entangled in a scandal over a budget-busting program to promote the use of alternative fuels.

But, he said by telephone: "it couldn't have happened without the clean-elections law to get on the playing field. It doesn't level the playing field, but it does put you on the field."

Mr. Blanchard's victory helped tip the balance in the State Senate from Republican domination to a 15 to 15 tie.

In Vermont, where a full public financing law took effect this year in the governor's race, the Progressive Party candidate, Anthony Pollina, qualified for nearly $300,000 in public financing. The incumbent, Dr. Howard Dean, a supporter of full public financing, had originally planned to use it as well, but when a court struck down the state's overall campaign spending limits, freeing his Republican opponent to far outspend him, the governor changed his mind.

The race, run amid rancor about a new state law creating marriagelike civil unions for gay couples, ended up being the most expensive contest for governor in Vermont history, with Dr. Dean and his Republican opponent, Ruth Dwyer, each spending about $1 million. Dr. Dean won with 50 percent of the vote.

Mr. Pollina took 10 percent, but more important, he told supporters after the election, he believed he had won the state's ear, and won the debates with his issues-based campaign.

In Maine, advocates of the Maine Clean Election Act have been closely tracking its results, and coming up with some definitive -- and, they say, heartening -- statistics:

Of all the races for the Legislature, 116 out of 352 candidates chose to run as full public financing candidates. Of those, 54 percent won. More women ran than usual, and contested primaries increased by 40 percent.

In all, about a third of the lawmakers who take their seats in January will have run with public financing.

Almost twice the percentage of the full public financing candidates were Democrats as Republicans -- 63 percent to 34 percent -- but Republicans reaped benefits, said Alison Smith, a chairwoman of Maine Citizens for Clean Elections, the coalition backing the law.

Republicans used the law successfully to recruit candidates for the State Senate, Ms. Smith said, and ended up shifting its balance from Democratic domination to a tie between Republicans and Democrats of 17 each (plus one Independent). Democrats in the House, she said, were also able to make gains by using the law to recruit candidates.

Here in Massachusetts, advocates are looking forward to seeing a Maine-like effect on elections.

"Right now, 71 percent of the races for the State Legislature are uncontested," and the state is ranked 49th in percentage of contested elections, said David A. Donnelly, director of Massachusetts Voters for Clean Elections. "So just on that measurement alone, the new campaign finance law will dramatically change the numbers of choices voters have."

The Clean Elections law in Maine is still new and open to refinement, however, and many candidates see room for improvement.

Donald Gean, executive director of the York County Homeless Shelter and a Democrat, found that his clean-elections campaign against an incumbent Republican was going nicely on a budget of about $13,000 until the end. Then, the state's Democratic Party, without consulting him, bought $7,000 worth of attack advertising against his Republican opponent, Michael J. McAlevey, he said. Such "independent expenditures" are allowed under the law.

The race turned ugly and Mr. Gean said that he lacked the money or the time to get his campaign back on track. He lost by about 3,000 votes out of about 19,000.

But he said that he would still "run clean" again.

"It's still the way to go," Mr. Gean said. "I ran the whole darned campaign owing nothing to any special interest group."