While writing a book has become a prerequisite for running for the presidency, it hasn’t quite caught on among vice presidential contenders.

As he is in many ways, Sen. Jim Webb (D-Va.) is the exception.

While other politicians’ books might be chalked up to their political ambitions, Webb has a pretty bulletproof excuse: I was an author before I was a politician.

It remains to be seen at which profession he excels more — his literary career is acclaimed and his command of language is something to behold for those who more often dredge in the prose of politicos and their ghostwriters — but Webb’s latest effort provides a roadmap of the place whence he would start that vice presidential journey.

Webb’s manifesto, A Time to Fight lays down the planks of what he calls a “fair and just America,” but it reads more like a do-it-yourself manual of American democracy. He describes democratic principles in broad and simple terms and offers a take or a solution that is, more often than not, lacking an overt political ideology.

That does not mean the book is free of politics. It’s sometimes frustrating when Webb doesn’t take a firm stand on a certain issue or offers something of an ambiguous solution — a politically typical one.

His main cure for the “many-headed crisis” in America right now is the reassertion of leadership, much of it from Congress. To gain that, he calls for the American people to make better choices about on whom they bestow the opportunity to lead. He urges the gamesmanship of political campaigns to cease and commends the activism of good and untainted knights in the political court.

It’s a nice thought, to be sure, and Americans of all stripes would be well-served to heed his advice about how to pick their congressmen and -women. But it’s also a monumental task that requires the kind of sophistication and involvement that appears to be beyond much of the American public.

At the same time, Webb’s positioning in the book lends itself well to a vice presidential campaign in 2008. In his presidential campaign, Sen. Barack Obama (D-Ill.) has been filling large venues with previously uninvolved masses and inspiring new classes of people to get involved in politics.

Journalists are frantically watching to see what compromises Obama makes as he intones a highly idealistic message. Webb fits that message because of his post- and bipartisan persona and personal history, which are composed of his books and his service in the military, including as Ronald Reagan’s Navy secretary.

As Obama eases into his status as the presumptive Democratic nominee, Webb has, whether purposefully or not, laid a marker. As his name is bandied about more and more in the Washington parlor game that is the veep-stakes, it’s surely worth keeping an eye on Webb’s self-described book tour.