The study by the Brennan Center for Justice, a group that supports overhauling campaign finance laws, said judicial candidates who spend the most on television advertisements won in 10 of 11 races.
Three-fourths of Senate races this month were won by the higher-spending candidate, as were 95 percent of House races, according to an Associated Press analysis of Federal Election Commission data.
The Brennan Center said more judicial candidates were raising more money and running more commercials than ever before. Candidates for nine states' supreme courts took to the airwaves in 2002 — Alabama, Idaho, Illinois, Michigan, Mississippi, Nevada, Ohio, Texas and Washington. In 2000, ads ran in only four states — Alabama, Michigan, Mississippi and Ohio.
This year, the study said, $7.4 million was spent on advertising in judicial races.
The center looked at advertisements for state supreme court judgeships that ran in the nation's 100 largest media markets.
"The public already believes that we have two systems of justice — one for those with money and one for those without," said Deborah Goldberg, deputy director of the Brennan Center's Democracy Program. "TV ads are expensive, and as money becomes more important to these elections, that cynicism can only grow."
Many candidates were helped by advertisements paid for by outside interest groups, the study said. Groups that paid for the ads did not have to identify sources of their money because their commercials did not specifically urge a vote for or against a particular candidate but were considered "issue advertisements."
Only a few interest groups are major players in such races. In 2000, about a quarter of the airtime was bought by only four interest groups. This year, ten interest groups accounted for 31 percent of the airtime. In some states, a single group dominated.
For example, in Michigan, the Chamber of Commerce paid for 58 percent of the judicial advertising to support two candidates. The rest of the airtime was purchased by the same two candidates, "making for a completely one-sided air war in Michigan," the report said.
"As interest groups expand their role in judicial elections, they shrink public confidence in fair and impartial courts," said Goldberg.
The only candidate who was able to win despite being outspent on the airwaves was Alabama Supreme Court Justice Harold See, who nevertheless ran more commercials than his opponent, the study found.
Concerns about the proliferation of advertising in judicial campaigns are only one worry about judicial elections. In some states, voters' choices in judicial races are strictly limited, with many candidates cross-endorsed by several parties or running unopposed.