In the summer of 2004 Jerome R. Corsi shot to the top of the best-seller lists as co-author of "Unfit for Command," the book attacking Sen. John Kerry's record on a Vietnam War Swift boat that began the larger campaign against Kerry's war credentials as he sought the presidency.

Now Corsi has released a new attack book painting Sen. Barack Obama as a stealth radical liberal who has tried to cover up "extensive connections to Islam" -- Obama is a Christian -- and questioning whether Obama's experimentation with drugs during high school and college ever ceased.

Significant portions of the book -- released by Threshold Editions, a division of Simon & Schuster that has as its chief editor, Mary Matalin, the former Republican operative -- have already been challenged as misleading or false in the days since it made its debut on Aug. 1.

But it is to make its first appearance on the New York Times best-seller list for nonfiction hardcovers this Sunday -- at No. 1. "The Obama Nation" is pushed along by a large volume of bulk sales, voter interest in Obama and an aggressive marketing campaign that already has included 100 author interviews with talk radio hosts including Sean Hannity and G. Gordon Liddy, Corsi said.

"The goal is to defeat Obama," Corsi said. He said he was also planning to assist several groups that intend to run ads against Obama this fall. Matalin said the book "was not designed to be ... a political book," but "a piece of scholarship."

Several of the book's charges are unsubstantiated, misleading or inaccurate. Corsi described most of the critiques as "nitpicking," such as when he cites the conservative website NewsMax.com that Obama attended an incendiary sermon of his former pastor, Jeremiah Wright, on July 22, 2007. However, Obama was giving a speech in Florida that afternoon.

Corsi also writes that Obama had "yet to answer" whether he "stopped using marijuana and cocaine" in college, asking, "How about in the U.S. Senate?" But Obama wrote in his memoir that he had "stopped getting high" in the early 1980s.

Obama's campaign has yet to weigh in heavily on Corsi's book, appearing to face the classic decision between the risk of publicizing the book's claims by addressing them and the risk of letting them sink into the public debate with no response. NEW YORK TIMES