Since he took over in 2003, Mr. Fitton has sought mainstream respectability for the organization.

It describes itself as a “nonpartisan educational foundation,” but Mr. Fitton says it is also a media organization. “We’re filling multiple roles here in a Washington where the traditional vehicles for government accountability have broken down,” he said.

Last year, he nominated Judicial Watch for three Pulitzer Prizes. He was told that because Judicial Watch was an advocacy group, it did not meet the Pulitzer committee’s eligibility criteria, a ruling he attributed to liberal bias.

If Mr. Fitton is seen as less flamboyant than his predecessor, he has been no less dogged in his pursuit of Mrs. Clinton. In 2009, Judicial Watch sued to prevent her from becoming secretary of state, claiming that an obscure clause in the Constitution prevented former members of Congress who voted to increase the salary of a government position from being appointed to that position.

For that matter, Judicial Watch is still suing the government to obtain a draft of the indictment against Mrs. Clinton that federal prosecutors prepared in 1998, when they were considering bringing charges against her in the Whitewater investigation.

“I think to say that they are not partisan would not be accurate,” said Representative Elijah E. Cummings of Maryland, the ranking Democrat on the House Committee on Oversight and Government Reform. “Look at the way that they have dealt with the Clintons. It seems as if they’ve been out to do them harm.”

According to Mr. Fitton, however, Judicial Watch’s persistence has been rewarded. “The documents we have uncovered in the last year or so are gobsmacking in terms of what they say about what Mrs. Clinton was up to, the depths of her criminality,” he said.

There is little doubt that the group has forced the release of government records that would otherwise have been kept from the public. More contentious is the claim that these documents illuminate Mrs. Clinton’s behavior, at least in the absence of the organization’s spin, which has broadly asserted that the Democratic presidential nominee used her position at the State Department to further the interests of her family’s foundation.