Some leading Democrats are eagerly – even desperately – looking for a liberal voice to offset the many conservative mouthpieces who have all but monopolized segments of the media. As a liberal answer to Rush Limbaugh, Bill O’Reilly and Sean Hannity, these Democrats are said to have settled on Al Franken, author of the new book, “Lies and the Lying Liars Who Tell Them: A Fair and Balanced Look at the Right.”

Mr. Franken had the good fortune to be sued by Fox News, evidently at the insistence of one of its stars, Mr. O’Reilly, host of “The O’Reilly Factor.” Mr. O’Reilly is a principal target of the book, and his picture appears on the cover. The lawsuit made the claim that the book’s title infringed on Fox’s trademark ownership of the phrase, “fair and balanced.” Even before the suit was laughed out of court, it had the unintended but predictable effect of boosting the book to first place on The New York Times bestseller list.

Confirmed left-wingers may have a great time thumbing through the 379 pages of refutation and denunciation of right-wingers including most of the leading conservative talk-show hosts. But much of the target audience of a projected liberal cable channel is bound to be offended and turned off by Mr. Franken’s stream of cornball wise cracks, profanity, scatology and blasphemy. That’s no way to convert the unconverted, let alone those persuaded that all liberals are filthy minded and chronic cheats, not to mention traitors to their country.

It’s a pity, because, along with the breezy gags, the book presents some enlightening facts based on solid research by the team that Mr. Franken organized during a visiting term at Harvard. For example, what he calls “Operation Ignore” is the story of how Condoleezza Rice, Vice President Dick Cheney, Defense Secretary Donald Rumsfeld and others in the Bush administration delayed and obstructed the continuation of a Clinton administration plan to destroy Osama bin Laden and his al-Qaida terrorist network – right up until Sept. 11, 2001. Much of the story had been told before, in newspapers and in Time magazine, but Mr. Franken’s version is an urgent reminder that a blue ribbon commission must investigate why the hijackers were so successful.

Considerably less urgent is his demonstration of the deliberate falsity of stories in the last presidential election purporting that Al Gore claimed to have invented the Internet and boasted that he and his wife were models for Erich Segal’s novel, “Love Story.” The humor in the latter claim, in fact, seems to have escaped Mr. Franken.

A liberal cable channel for news and comment would complete the general cacophony now half done by current cable offerings, but if it is going to be persuasive it will need to limit the silliness too often evident in Mr. Franken’s book.