Nine months before the first ballot has been cast in the 2012 presidential nominating process, a casual impression has metastasized into a hard husk of conventional wisdom: The Republican field of 2012 is weak. That's the word that's invariably used: weak, as in presumably not strong enough to produce a candidate who could defeat Barack Obama.

This judgment seems rash -- the field hasn't fill out yet and the first primaries are eight months away -- but it's certainly caught on within the punditry, left, right and center.

"Every one of the top candidates comes with a potentially huge flaw," proclaims Chris Matthews. "It's the weakest field any of us have seen in our lifetime," Mark Halperin of Time magazine proclaimed flatly. "The elephant in the room in this Republican field is that it is broad but fairly weak," Daily Beast columnist John Avlon stated on "Good Morning America." "The field," added Charles Krauthammer, "is split and weak."

Alexander Trowbridge had fun with this on Politico's "Echo Chamber" feature. But Republican activists have joined in the "weak field" chorus, too, a mantra Democrats have been only too pleased to repeat. "Unless they're working for one of these guys," longtime Democratic campaign consultant Bob Shrum says, "they think this is a very weak field."

Shrum was showing restraint. Even some of the GOP candidates' aides have repeated the "weak field" mantra.

"This is," Jon Huntsman's would-be campaign manager, John Weaver, told Time, "the weakest Republican field since Wendell Willkie won the nomination on the sixth ballot in 1940." Former Republican Party Chairman Jim Gilmore added recently that the Republican field is filled with "clowns."

There appears to be little historical validity to these claims, which are almost entirely subjective, and anyway it's beside the point: For starters, the Republicans don't need a strong "field," they need a strong nominee. One viable candidate must emerge from the field -- that's all.

"The opposition field to a sitting president usually seems weak until there is a nominee," says GOP strategist Mark McKinnon. "But, when the nominee gets up on the convention stage and gives their acceptance speech, they suddenly appear to have a cape and an ‘S' on their chest."

That's not always the case, but it's pretty much what happened in 1992, the last time the out-of-power party unseated an incumbent president. Then, like now, the slate of Democratic challengers was widely characterized as unimpressive. So much so that New Jersey's Sen. Bill Bradley was being urged to enter the race -- just as New Jersey Gov. Chris Christie is today.