During an interview with National Public Radio in which he was supposed to be making the case for McCain, Lawrence Eagleburger, a former secretary of state under President George H.W. Bush, was frank in his response to whether Palin was ready to assume the presidency, if need be.

From The Huffington Post:

“It is a very good question,” he said, pausing a few seconds, then adding with a chuckle: “I’m being facetious here. Look, of course not.”

Eagleburger explained: “I don’t think at the moment she is prepared to take over the reins of the presidency. I can name for you any number of other vice presidents who were not particularly up to it either. So the question, I think, is can she learn and would she be tough enough under the circumstances if she were asked to become president, heaven forbid that that ever takes place?

“Give her some time in the office and I think the answer would be, she will be [pause] adequate. I can’t say that she would be a genius in the job. But I think she would be enough to get us through a four year… well I hope not… get us through whatever period of time was necessary. And I devoutly hope that it would never be tested.”

Following former Secretary of State Colin L. Powell’s cross-party endorsement of Sen. Barack Obama, McCain has repeatedly pointed to his own endorsements from five other former secretaries of state, including Eagleburger, each of whom he said he admires enormously.

However, if Eagleburger is correct in his assertion that in time, Palin could become “adequate,” it would seem to call into question McCain’s sincerity when he said, “the Oval Office in wartime is no place for on-the-job training.”

The most respected Republican foreign policy voice in America will speak on “Meet The Press” Sunday, sparking rumors about a potential presidential endorsement. Sen. Barack Obama’s campaign will be listening closely.

Obama spokesperson Linda Douglas said today that she has no news on the Powell front, but the campaign would obviously love his endorsement.  “We would welcome the support of somebody with such a distinguished and honorable career as General Powell,” she told me this morning, as Obama’s plane flew to Virginia for a rally.

Obama has previously cited Powell as a potential member of his administration, and the two have been in touch before. “I know they talk from time to time about foreign policy matters,” Douglas said, though she did not know the last time they spoke.

Powell is widely viewed as a thoughtful public servant with credibility (and experience) in both parties.  Since leaving the Bush administration, he has been cast in journalistic accounts as a cautious conservative who sounded alarms about President George W. Bush’s approach to Iraq. In the new movie “W.,” Powell is the only voice of reason in a bunker packed with incompetent neocons.

Warnings given in private about policy decisions cannot offset Powell’s hawkish presentation to the U.N. on the eve of the Iraq war. But unlike so many war cheerleaders in politics and the media, he owned up to his mistakes. On national television, Powell called the U.N. address a “blot” on his record.

In a tough period for the GOP, Powell remains his party’s most beloved national figure. During his tenure as secretary of state, his unfavorable rating held to a remarkable five percent — more in line with Santa Claus than a Bush administration official.

Powell’s unusually strong support across the political spectrum, burned into the public imagination in serving Bill Clinton and two Bushes makes him one of the few people who’s endorsement could actually influence voters.

“[An endorsement] would get several days worth of coverage,” said Time’s Mark Halperin on MSNBC today. “I think for some voters who are wary about voting for an African-American who they don’t know, who doesn’t have experience in national security, [Powell would be] a validator who is almost unique in America today.”

If Powell endorses anyone, his views on Iraq and past praise for Obama make a Democratic nod seem more plausible.