A major reason why premature veep speculation is prematurely wrong is because the presidential nominees have not made up their own minds or are about to change them. Vice presidential searches can shift direction in an instant even without the electric shock of a Tom Eagleton-like secret coming out during the final round of vetting. In 2008, according to Game Change by John Heileman and Mark Halperin, “For much of August, McCainworld pursued the [Joe] Lieberman option with a singular focus.” That initial preference, shared both by the candidate and his top advisers, was only abandoned when the McCain team belatedly realized the extent of potential right-wing rage over a potential running mate with liberal positions on most social issues.

In 1988, it was not until the Friday before the Republican Convention that George H.W. Bush got around to canvassing his top advisers for their veep picks. (Chief strategist Lee Atwater, of course, had already commissioned a raft of polling). While Dan Quayle had few enthusiastic supporters among the Bush inner circle, he also had the fewest detractors. Quayle’s only fervent opponent was campaign chairman James Baker. As a result, it is universally assumed that it was Baker who leaked Quayle’s name to the New York Times in the hopes of arousing opposition from Republicans who saw the Indiana senator as a real-life Alexander Throttlebottom. But Baker made a strategic error, as former Washington Post reporter Paul Taylor tells it in his 1990 book, See How They Run. Quayle was such a non-entity in the Senate that, according to Taylor, “even after the Times piece came out, virtually no one considered Quayle as a serious possibility.”

How I remember that egg-on-the-face feeling at the 1988 GOP Convention. As a senior writer for Time, I was learning the shocking life lesson that late nights in the bar and early morning interviews do not mix, especially in New Orleans. So the Monday morning of the convention, with Bush’s choice still under wraps, I rolled over when the hotel wakeup call summoned me to a Time breakfast with a long-shot vice-presidential possibility—a callow, golf-obsessed senator named Quayle. I still cringe with embarrassment that later that week I had to borrow a colleague’s tape of that breakfast in order to write the Time cover story about Bush’s quicksand problem with Quayle.

I am not a press-criticism purist who naively believes that a few high-minded lectures can stamp out bottom-feeding rumor-mongering about the bottom of the ticket. My dreams of reform are far more modest: Permanently deleting from news stories and TV commentary John Nance Garner’s (bowdlerized) claim that the vice presidency is “not worth a warm bucket of spit” and John Adams’s lament that the job is “the most insignificant office that ever the invention of man contrived or his imagination conceived.”

Okay, there are a few other items on my vice-presidential short list. Reporters and pundits should not pretend to know more than they do in portraying the inner thinking in the Romney camp. This is a moment when most big-name Republican consultants are either out of the loop or have an agenda like boosting a client whose image would be enhanced by a walk-on role in the vice-presidential pageant. So more phone calls generally lead to more conventional wisdom rather than to more insight. Add to the mix the deliberate self-serving leaks that may come from inside the Romney camp in order to signal to independent voters and GOP activists that the almost-nominee is considering women or Latinos or uncompromising social conservatives.

The only point of comfort for the political press corps is they are not the only ones who have blundered in the mug’s game of picking a vice president. Presidential nominees have not done that well either. It is worth recalling that the last three losing vice-president candidates were Sarah Palin (discredited), John Edwards (indicted) and Joe Lieberman (drummed out of his party). That should be enough to give anyone—reporter or political strategist—an intense feeling of humility during the next four months.

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Walter Shapiro just chronicled his ninth presidential campaign. He writes the “Character Sketch” political column for Yahoo News. Follow him on Twitter @WalterShapiroPD.