For those of us who have been writing critically about John McCain over the years, keeping tabs on the 2008 presidential campaign through the media is a bit like getting your war news via Saddam Hussein’s old information minister: The street names may be right, but the big picture looks funny.

“No other modern politician has received as much favorable press as John McCain has in the past decade,” write (plainly irritated) David Brock and Paul Waldman in “Free Ride: John McCain and the Media.” “The rules are simply different for McCain.”

Boy, are they. Though he flip-flops and prevaricates like any politician, McCain all but has the phrase “straight talker” tattooed on his skull-plate. A lifetime Beltway insider and third-generation naval officer with an heiress wife and an heiress mother is still referred to, without irony, as a “Man of the People.” And though his heavily interventionist governing philosophy, both at home and abroad, is spelled out in his five easy-to-find books, he continues to receive mash notes from newspapers like the Des Moines Register for being a man who, because “he knows war,” would be “reluctant to start one.”

Such funhouse-mirror distortions are more than just giggle-worthy. Partly because of his reliably sympathetic portrayal in the media, McCain – who was advocating pre-emptive war against “rogue states” four years before it ever occurred to George W. Bush – nonetheless won by ratios of two to one among GOP primary voters who described themselves as “anti-war.”

So if nothing else, “Free Ride” comes as a necessary corrective. Lefty partisan co-authors Brock and Waldman work for Media Matters for America, a “progressive” nonprofit “dedicated to comprehensively monitoring, analyzing and correcting conservative misinformation in the U.S. media.” Therein lies the book’s strength and weakness. There’s nothing like a bit of the old political bile – especially when it pays! – to focus the mind and support staff on cataloguing the sins of the other team while bashing the media for failing to notice.

Thus the authors upbraid Beltway journalists for failing to recognize that “McCain has an act, and not having an act is his act.” When the candidate bashed President Bush’s Iraq policy in 2007, ageless Washington Post columnist David Broder pronounced that “candor, even belatedly, becomes him.” When his campaign stumbled over immigration that spring, Newsweek was there to solemnly proclaim that “it may be because he is not, at heart, a politician. He is a warrior.”

How did a Republican end up charming the liberal press? Brock and Waldman rightly point out three reasons: McCain’s heroic war record, his “anti-politician” support for campaign finance reform and the copious amounts of access he has consciously given national reporters for the past two decades. “The McCain-Feingold bill in particular,” they write, “became a vessel into which the press could pour all of its disgust with the practice of politics.”

But media criticism works best when new interpretive light is shined on the subject being mis-covered. And it’s here that the authors’ partisan agenda and ideology get the worst of them.

They argue, improbably, that McCain has always been a “staunch” and “reliable conservative,” in the tradition of Barry Goldwater. In fact, McCain’s famous regulatory zeal on the Senate Commerce Committee – meddling into the affairs of amateur athletes, Hollywood marketers and tobacco companies – has been the opposite of Goldwater’s principled libertarianism, and indeed the younger maverick never did understand why the man he replaced in the Senate failed to fully embrace him.

And what about McCain’s furious tack to the left from 1999 to 2003, when he opposed Bush tax cuts on class warfare grounds, co-sponsored a patients’ bill of rights, and voted to federalize airport security, all while trumpeting the career of trust-buster Teddy Roosevelt and flirting openly with defecting to the Democrats? “A few well-chosen breaks,” they claim. Well OK then.

Lacking any ability or willingness to analyze McCain’s peculiar strain of National Greatness Conservatism, Brock and Waldman fill the pages by exaggerating the extent to which McCain is handled with kid gloves (The New York Times in particular has been disproving that notion almost every day); complaining about journalists referencing his Vietnam imprisonment, and relying on such crude measuring sticks as the voting scorecards of activist groups.

The results correct some myths, but erect new ones in their place.

Matt Welch, editor-in-chief of Reason magazine, is the author of “McCain: The Myth of a Maverick.”

Free Ride: John McCain and the Media

by David Brock and Paul Waldman

Anchor Books