The marvelous paradox of politics is that it is the only field in which lack of experience is considered a job qualification. Or, conversely, in which extensive experience is cited as a negative.

Consider Mitt Romney’s latest line, a none-too-subtle jab at Texas Gov. Rick Perry: “Career politicians got us into this mess and career politicians can’t get us out!” Sarah Palin took a similar swipe in Perry’s direction, inveighing against a “permanent political class.”

One could point out that Romney’s critique is a bit odd coming from someone who’s been in political office or running for one for the better part of two decades. One could note that Palin, other than her early stint as a sportscaster and later role in reality TV, has worked mostly in government jobs, from the Wasilla City Council to the Alaska governorship.

My point is different: that the attack on the “career politician” is as misguided as it is familiar. Your career politician is my devoted public servant.

ODD LINE TO TAKE

Imagine this line of argument applied to another job. “Unlike my competition, I haven’t spent my life in the oil industry,” an aspirant to the CEO post at Exxon Mobil announces. “I’m no career retailer,” crows a would-be Walmart head.

Indeed, former Hewlett-Packard CEO Carly Fiorina made this point during the 2008 presidential campaign.

“Well, I don’t think John McCain could run a major corporation,” said Fiorina, then a senior McCain adviser. “I don’t think Barack Obama could run a major corporation. It is a fallacy to suggest that the country is like a company. So, of course, to run a business, you have to have a lifetime of experience in business, but that’s not what Sarah Palin, John McCain, Joe Biden or Barack Obama are doing.”

Fiorina is demonstrably wrong, by the way, about the categorical imperative of business experience: see, for example, Dick Cheney’s tenure at Halliburton or Donald Rumsfeld’s at G.D. Searle and General Instrument.

And, of course, her belief in the imperative of experience in the business world did not translate into a belief in the similar imperative of political grounding. Running for the U.S. Senate in California two years later, Fiorina blasted incumbent Democrat Barbara Boxer for “her 28 years of being a career politician in Washington, D.C.” You may notice that she did not become Sen. Fiorina.

My point isn’t that previous political experience is a necessary qualification for elective office, even high elective office.

It’s not. Indeed, it’s healthy to have a mixture of experiences and backgrounds — a Congress that includes former doctors and business executives along with former state legislators and ex-governors. Politics isn’t rocket science; it doesn’t require an advanced degree or specialized expertise.

But neither is political experience irrelevant — or the negative that Romney, Palin & Co. imply. The romantic image of the citizen-legislator, Cincinnatus called to service and then returning to his plow, is a constant theme of American political life.

Yet a government composed entirely of Cincinnati would be dangerously ineffective. As James Madison wrote in Federalist 62: “A good government implies two things: first, fidelity to the object of government, which is the happiness of the people; secondly, a knowledge of the means by which that object can be best attained.”

In other words: Wanting to do the right thing doesn’t matter if you don’t know how to get it done. The political short-timer has little interest in forging relationships or building the coalitions necessary for productive compromise. The reviled “career politician” may have seen this play before. The more complicated the issues, from health care to defense spending, the more valuable the institutional knowledge.

NOT ENOUGH TIME

I’d argue, for example, that President Obama’s current difficulties stem less from his being a “career politician” than from the fact that his political career was so brief before he won the White House. Experience matters, even in politics. This is why Vice President Joe Biden, with long-standing relationships in Congress, brings value to the Obama White House. It is why governorships have proved to be such an effective preparation for the presidency.

No “career politician” — that is, no one who’s managed to win re-election — is going to be dumb enough to run an ad promoting himself as such.

Surely, Romney won’t be the last candidate to deploy the career politician epithet against a threatening opponent.

But every time this phrase is used, it’s worth wondering why the attacker professes to so disdain the very vocation he so avidly seeks.

Ruth Marcus is a columnist for The Washington Post. She can be contacted at:

ruthmarcus@washpost.com