Four men charged with trying to tamper with a senator’s phones — including a conservative activist known for targeting ACORN — hoped to record embarrassing hidden camera footage to document allegations her staff was ignoring calls critical of her stance on health care reform, an attorney for one of the four said Thursday.

Attorney J. Garrison Jordan denied the four men were trying to disable or wiretap the phones in Sen. Mary Landrieu’s office at a federal building in New Orleans.

“You’re dealing with kids,” he said. “I don’t think they thought it through that far.”

Instead, Jordan said, they hoped to get embarrassing video footage of her staff handling constituent calls.

The four accused in the scheme include James O’Keefe, made famous by posing as a pimp and targeting the community-organizing group ACORN in hidden camera videos.

Jordan said his client, Robert Flanagan, the 24-year-old son of a federal prosecutor in Louisiana, did not intend to break the law when he entered the office posing as a telephone worker Monday.

No matter their intentions, the four face the serious charge of entering federal property under false pretenses for the purpose of committing a felony, which carries up to 10 years in prison. They are free on $10,000 bail.

Charged along with O’Keefe and Flanagan were Joseph Basel, 24, of Minnesota and Stan Dai, 24, of the Washington, D.C. area. The four are due back in court Feb. 12.

Authorities said O’Keefe was using his cell phone to try to capture video of two of his fellow defendants in Landrieu’s office before their arrest. The two posing as telephone repairmen — wearing fluorescent vests, tool belts and hard hats, one of which had a hidden camera — asked to see the phones at Landrieu’s office. The fourth is alleged to have waited outside in a car with a listening device to pick up transmissions.

O’Keefe has declined to discuss what he and the others were doing in Landrieu’s office. Late Wednesday he told his Twitter followers that the government “concedes no attempt to wiretap.”

Last month, protesters marched in front of Landrieu’s office in Baton Rouge to criticize her support for health care legislation and complain that they couldn’t get through on her office phones. Landrieu said at the time that her office received a high volume of calls.

“Our lines have been jammed for weeks, and I apologize,” Landrieu said in interview with The Advocate of Baton Rouge in December. “But no amount of jamming is going to keep me from supporting a good work for Louisiana and the nation.”

Andrew Breitbart, whose biggovernment.com site launched O’Keefe’s ACORN videos and who has since hired O’Keefe as a contributor, also downplayed the federal case.

“Their uniforms were outlandish,” Breitbart said in an interview. “This was like ‘Hee Haw,’ a blatant clown-nose-on spectacle to make a salient political yet mildly humorous point.”

O’Keefe hinted last week that he had a new, high-profile stunt in the works. Four days before he was charged in connection with the Landrieu incident, he promised his audience at a conservative think tank’s luncheon they would be hearing about a project he was working on in New Orleans.

He wouldn’t elaborate, according to people who heard his speech at the Pelican Institute’s event last Thursday in New Orleans.

“He just sort of alluded to the fact that we would all find out real soon. And we did,” said Audra Shay, a Mandeville resident and chairwoman of the Young Republican National Federation.

Flanagan worked part-time with the institute, writing for its blog and helping with luncheons.

During the luncheon last week, audience members peppered O’Keefe with questions about Landrieu, but he didn’t indicate that she was a target of his project, said Robin Edwards, a Baton Rouge resident and co-founder of the Louisiana Tea Party Federation.

“He just said he had a project going in New Orleans, but he wouldn’t say what it was,” Edwards said. “I figured it had something to do with ACORN.”

Shay said O’Keefe told audience members to “stay tuned” for the results of his New Orleans project.

“Everybody in the room knew something was going on, but nobody knew what the hell it was,” she said. “I never thought it was going to be this.”

Shay said O’Keefe repeatedly stressed that he hadn’t done anything illegal on his earlier investigative projects.

“It’s bizarre, because the guy is not stupid,” she said.

Shay said she spoke with Basel, who attended the luncheon with O’Keefe, and asked him about booking O’Keefe for a leadership conference hosted by the federation. In the aftermath of O’Keefe’s arrest, she didn’t know if she would follow through with an invitation.

Michael Madigan, O’Keefe’s lawyer, said Wednesday that his client was not trying to wiretap or interfere with Landrieu’s phones, but he would not explain why O’Keefe was there. He also would not say whether O’Keefe was working for someone or was on his own.

“The truth will come out,” said Madigan, a Washington lawyer who represented Sen. Howard Baker, the Republican who famously asked during the Watergate investigation, “What did the President know and when did he know it?”

Pelican Institute: www.pelicaninstitute.org

BigGovernment.com: www.biggovernment.com

Sen. Mary Landrieu’s official site: www.landrieu.senate.gov