The long knives have been drawn and sides chosen over Kitty Kelley’s new book that purports to uncover generations’ worth of scandal in the Bush political family. It’s now a political football, but there are far darker books on the shelves of your local bookselling conglomerate. Books you really don’t have to read.

At least Kelley’s book seems to have been written with the straightforward and time-honored intent of skewering those in power. But, judging by the titles, numerous other authors don’t care whether you open their books or not. What’s on the cover telegraphs the contents completely — and the contents seem always to involve a highly partisan political statement, repeated at length.

Gone are the quaint days of Bob Woodward’s Plan of Attack, which, while uncomfortable for the subject (George W. Bush’s war prosecution), seemed to promise illumination that went beyond party ideology. The fact that both Democrats and the White House embraced it as supporting their cause is testament enough to that.

But now, bestseller lists give us, among many other similar selections, Unfit for Command and Bush Must Go, purely partisan statements that need not be read for their effects to be felt.

And that’s the point. To an outside observer, the book publishing business seems to have been taken over by agenda-driven political strategists. So many of the books on offer are transparently part of a broader influence campaign, a campaign that includes political advertisements in battleground states, diatribes on key radio talk shows, rebuttal articles in national print publications, and (if all goes well) a slot on “Hardball With Chris Matthews” or a similar show. Instead of selling the book and the ideas it contains, the authors sell the statement the book makes, all in the service of advancing the Red or Blue ideology.

So what? The intellectual marketplace has always been a bustling place, and has always associated itself with politics and public issues, hasn’t it? Indeed, the most soaring and durable argument against censorship, John Milton’s Areopagitica (1644), was itself a political tract.

But things have changed. The tail now wags the dog. Books used to lend their credibility to political arguments by being careful, well reasoned expositions. Instead, books now gain credibility by associating themselves with one of two competing ideologies. And such books, in turn, provide tactical ammunition for their adherents. Because books still add credibility, by virtue of — well, by virtue of the fact that they’re books.

At a time when a diminishing few read books at all, this is a problem. The place that used to be the province of reasoned debate is now the territory of angry shouts. Real thought is being squeezed out.

The solution will not be easy. It will demand restraint, restraint from the publishing houses, restraint from the political marketing machines, and, above all, restraint from the writers.

Perhaps this is too much to ask. There is a seductive symbiosis between the business of publishing and political marketing. Ideology-driven books have a ready and free marketing campaign in place in the form of the national political committees. No, it is writers who are our best hope. They alone may be able to resist the temptation to feed the political-publishing vicious circle.

So, a note to those authors sitting down to tap out their manifestos. Stop after the first chapter, and ask yourself: Is this really a book, or just a statement made repeatedly? Do I hope the book will be read, or do I hope the book will advance my party? If the latter, we the marketed-to humbly request that you stop right there and post your piece to a web log or send it off to a weekly journal of opinion.

For the honorable shelves of the nation’s libraries, institutions that dutifully purchase the output of publishers as a public service, are sagging under the weight of partisan vitriol.

Spare them.