At critical moments before and during Ronald Reagan's presidency, his admirers would urge that he be allowed to be himself - rather than the far less authentic and appealing facsimile served up by his handlers.

"Let Reagan be Reagan," they would urge, confident the man would fare well if left to his own talents and judgment. Time and time again that proved to be the case as his common-man qualities, native intelligence and utter decency allowed him to connect with and secure the support of the American people.

This lesson is worth recalling now, on the eve of a possibly make-or-break vice presidential debate between Republican Sarah Palin and her Democratic rival, Sen. Joseph Biden. The outcome - and the fate of the Republican ticket - may turn on whether her handlers "Let Palin be Palin."

To be sure, there are powerful factors arguing for doing otherwise. While the governor of Alaska has more executive experience than Barack Obama and Joe Biden combined, she is a relative newcomer to many national and certainly international issues. While her state's geography, energy resources and role in the national defense give her a grounding - by osmosis, if nothing else - in some of the most important foreign and security policy issues of the day, she has not been dabbling in and debating them for more than three decades, as has the senior senator from Delaware.

Understandably then, Sen. John McCain's campaign has sought to give his running-mate a crash course in the sorts of issues likely to feature in the Palin-Biden debate on Thursday night. They have largely kept her away from the press, with the notable exception of interviews with ABC's Charlie Gibson and CBS' Katie Couric, which demonstrated the perils of trying to give her an overnight public policy makeover, one that threatens to serve her, her party and the country poorly.

Of particular concern is the prospect that her head is being filled with the nostrums of one inveterate handler, former Secretary of State Henry Kissinger. The risks of channeling the man Ronald Reagan ran against in 1976 as much as he did Gerald Ford was on display during Friday night's presidential debate between John McCain and Barack Obama.

As Mr. McCain was properly taking his rival to task for the latter's stated willingness to meet without preconditions with the leader of Iran, Mr. Obama retorted that one of the Republican candidate's own senior advisers, Mr. Kissinger, had recommended such engagement. The debate corkscrewed into a "no, he didn't," "yes, he did" stand-off the upshot of which was that Mr. Kissinger apparently doesn't think the next U.S. president should meet with Mahmoud Ahmadinejad, but does believe his administration should hold meetings with other representatives of that genocidal maniac's regime.

That's pretty much what Messrs. Obama and Biden are saying now. Heaven help the nation - and the Republican ticket - if the choice between Mr. McCain and Mr. Obama turns out to be which of the minions of our time's Adolf Hitler we seek to appease, Heinrich Himmler or Joseph Goebbels.

Unfortunately, Iran policy is not the only place where the common sense and moral clarity that Sarah Palin seems fully capable of bringing to bear - the sort of clarity that was the very essence of Ronald Reagan's personal approach to security policy -would be imperiled by her eminent mentor. On two other issues, Mr. Kissinger has staked out positions in recent years that are not only indefensible but much more similar to the stances embraced by the Democratic ticket than those of Mrs. Palin's running-mate.

Take for example, Russia. Mr. Kissinger - whose consulting firm has long had commercially lucrative relationships in Moscow - has for years urged accommodation with Vladimir Putin and his kleptocracy, even as it systematically stifled democracy at home and increasingly threatened it abroad. (In an earlier era, Mr. Kissinger justified appeasing the Kremlin with detente because he was convinced the Soviets were going to win the Cold War.)

The Bush administration, to its shame and now regret, followed the advice proffered in innumerable seances with the former secretary of state. It would be disastrous for Mrs. Palin to endorse it, especially since her running-mate has taken so much more robust a stance toward the Kremlin, both before and after its invasion of Georgia.

Then there is Mr. Kissinger's endorsement of the idea of U.S. denuclearization. He has lent his name and prestige to an initiative that would, as a practical matter, make the world a much more dangerous place since our enemies will surely not follow our example if we get rid of our nuclear arsenal. Here again, as with Iran and Russia, the Kissinger position is closer to Barack Obama's than to John McCain's. It is certainly not consistent with the national interest.

From here on out, and most especially Thursday night, Mrs. Palin should be herself. She doesn't have to know everything and shouldn't pretend she does. What she needs to communicate is that - like Ronald Reagan and, for that matter, like Harry Truman - she will bring to the job her native American common sense instead of some establishment pedigree and lousy judgment. (See Andy McCarthy's devastating critique of Joe Biden).

Mrs. Palin, use your platform on Thursday to embrace American exceptionalism, defend our sovereignty and promise to build our national power and to employ it wisely in defense of both. The public - if not the policy establishment and the media elite - will embrace you, as they did the Gipper. Just let Palin be Palin.