WASHINGTON -- It was the first public allegation that CBS News used forged memos in its report questioning President Bush's National Guard service -- a highly technical explanation posted within hours of airtime, citing proportional spacing and font styles.

But it did not come from an expert in typography or typewriter history, as some first thought. Instead, the Los Angeles Times has found that it was the work of Harry W. MacDougald, an Atlanta lawyer with strong ties to conservative Republican causes. He helped draft the petition urging the Arkansas Supreme Court to disbar then-President Bill Clinton following the Monica Lewinsky scandal.

The identity of "Buckhead," a blogger known previously only by his screen name on the Web site freerepublic.com and lifted to folk-hero status in the conservative blogosphere since last week's posting, is likely to fuel speculation among Democrats that the efforts to discredit the CBS memos were engineered by Republicans eager to undermine reports that Bush received preferential treatment in the National Guard more than 30 years ago.

Republican officials have denied any involvement among those debunking the CBS story.

Reached by telephone yesterday, MacDougald, 46, confirmed that he is Buckhead but declined to answer questions about his political background or how he knew so much about the CBS documents so fast. "You can ask the questions, but I'm not going to answer them," he told The Times. "I'm just going to stick to doing no interviews."

Until The Times identified him by piecing together information from his postings over the past two years, MacDougal had taken pains to remain in the shadows -- saying the credit for challenging CBS should remain with the blogosphere as a whole, and not one individual.

"'Freepers' collectively possess more analytical horsepower than the entire news division at CBS," he wrote in an e-mail, using the slang term for users of the freerepublic site.

MacDougald is a lawyer in the Atlanta office of the Winston-Salem, N.C.-based firm Womble Carlyle Sandridge & Rice and is affiliated with two prominent conservative legal groups, the Federalist Society and the Southeastern Legal Foundation, where he serves on the legal advisory board.

Founded in 1976, the Southeastern Legal Foundation has fought affirmative action and domestic-partner benefits for government employees, and successfully challenged a Clinton-administration plan to use proportional sampling, rather than a hard count, to estimate population in the 2000 Census.

MacDougald helped draft the foundation's petition in 1998 that led to the five-year suspension of Clinton's Arkansas law license for giving misleading testimony in the Paula Jones sexual harassment case.

And he assisted in the group's legal challenge to the campaign finance law sponsored by Sen. John McCain, R-Ariz., and Sen. Russ Feingold, D-Wis. The challenge, ultimately presented to the U.S. Supreme Court, was funded largely by the Southeastern Legal Foundation in conjunction with Sen. Mitch McConnell, R-Ky., the law's chief critic, and handled by former Clinton investigator Kenneth W. Starr.

The Supreme Court upheld the law, which banned unlimited contributions from corporations to federal candidates and political parties.

MacDougald is also a Republican appointee to the Fulton County Board of Registration and Election.

Last week, MacDougald once again plunged into a politically charged controversy -- but this time his participation was anonymous. Operating as "Buckhead," which is also the name of an upscale Atlanta neighborhood, MacDougald wrote that the memos that CBS's "60 Minutes" presented on the evening of Sept. 8 as being written in the early 1970s by the late Lt. Col Jerry B. Killian were "in a proportionally spaced font, probably Palatino or Times New Roman."

"The use of proportionally spaced fonts did not come into common use for office memos until the introduction of laser printers, word-processing software and personal computers," MacDougald wrote on the freerepublic Web site. "They were not widespread until the mid- to late '90s. Before then, you needed typesetting equipment, and that wasn't used for personal memos to file. Even the Wang systems that were dominant in the mid-'80s used monospaced fonts.

"I am saying these documents are forgeries, run through a copier for 15 generations to make them look old. This should be pursued aggressively."

The Sept. 8 late-night posting -- written fewer than four hours after the CBS report was aired -- resulted in a flurry of sympathetic testimonials from fellow bloggers, spreading within hours to other sites.

The next day, major newspapers such as The Los Angeles Times and the Washington Post began consulting forensic experts and reporting stories that raised similar questions.

The network has insisted that the four memos, dated from 1972 and 1973, had been authenticated by the network's experts and by "close associates" of Killian, who confirm "that the documents reflect his opinions and actions at the time."

The memos showed Killian resisting pressure by a higher-up to "sugar coat" Bush's performance evaluation and ordering Bush to take a physical examination so he could keep flying.

CBS has cited an expert, Bill Glennon, an information technology consultant, who said IBM electric typewriters that were in use in 1972 could provide proportional spacing and the superscript -- the small "th" -- evident in the disputed memos.

The network also has sought to counter the arguments by referring to a typewriting script distributor, who says the typing style in the memos has been available since 1931. Moreover, CBS points out, some of the lettering in question was evident in Bush's military records previously released by the White House.

Still, when Killian's former secretary came forward this week to say she did not believe that the memos were authentic either, anchor Dan Rather and other network executives stopped asserting that the memos were real. They said they would "redouble" efforts to resolve unanswered questions.

While bloggers and some conservative activists hailed Buckhead as a hero in their longtime efforts to paint the mainstream media as politically biased, some Democrats and even some conservative bloggers have marveled at Buckhead's detailed knowledge of the memos and wondered whether that suggested a White House conspiracy.

Democratic National Committee Chairman Terry McAuliffe speculated openly to reporters that the whole thing could have been orchestrated by White House political adviser Karl Rove. The Bush campaign called the allegation "nonsense."

The White House had access to the memos prior to the Sept. 8 broadcast. CBS delivered copies to White House communications director Dan Bartlett on the morning of its broadcast, so he could discuss them in an interview with anchor Dan Rather.

McDougald is not a big financial contributor to political causes, having donated $250 to the Georgia Republican Party in 2002, when Christian Coalition founder Ralph Reed was chairman. Reed is now a senior strategist for the Bush campaign.