When John McCain’s campaign released his new “economic plan” on Monday, it also put out what was advertised as an endorsement of said plan by 300 economists. This mattered because the plan was focused heavily on one highly dubious promise — that McCain would balance the federal budget by the end of his first term — and featured a variety of proposals — particularly a “gas tax holiday” — that have been heavily mocked by economists in the past.

Could 300 economists be wrong?

Well, turns out that’s not the relevant question, which is: Can a general statement of support from 300 economists be used to hype a new “economic plan” they haven’t read?

Alexander Burns and Avi Zenilman of the Politico decided to pick up the phone and call some of these worthies, and found they were a bit baffled at being touted as supporting the new McCain document.

In interviews with more than a dozen of the signatories, Politico found that, far from embracing McCain’s economic plan, many were unfamiliar with — or downright opposed to — key details. While most of those contacted by Politico had warm feelings about McCain, many did not want to associate themselves too closely with his campaign and its policy prescriptions.

This isn’t that surprising, since the McCain campaign “began collecting signatures from economists several months ago, with the intention of showing support for McCain’s broad economic priorities, rather than the specific items in his Jobs for America proposal.”

And the economists’ statement itself doesn’t mention many of the features of the new “plan,” including the balanced-budget pledge, the gas tax holiday, and the suggestion that “victory” in Iraq and Afghanistan will produce a giant budget bonanza.

Moreover, it would be a bit difficult for the economists to endorse a “plan” with so many vague goals and unidentified details.

So the real meaning of the statement released on Monday is that 300 practitioners of the dismal science (many of them appointees in Republican administrations over the years) support John McCain for president. Or make that at least 299, since the Politico’s short list of random calls turned up one economist who said he actually supports Barack Obama.