In a presidential race in which John McCain seems to be holding the weakest cards — his age, limited campaign money, the albatross of an unpopular president around his neck — he has gotten a favorable shuffling of the deck from a Barack Obama surrogate.

The blunder of retired Army Gen. Wesley Clark in questioning McCain’s military service as a recommendation for the presidency has spotlighted the Arizona senator’s one ace — the patriotism card — at a time his campaign could stand a boost.

Clark’s remark on the CBS News show “Face the Nation,” that “I don’t think getting in a fighter plane and getting shot down is a qualification to become president,” was about the dumbest gratuitous remark the general could have served up to help McCain, and hurt himself.

Any lingering speculation that Clark, a former NATO supreme commander, might be on Obama’s short list as his running mate was self-immolated by the impolitic observation.

There is always danger of military figures who are neophytes in politics gumming up the works. But not since Air Force Gen. Curtis LeMay’s bizarre defense of the use of nuclear weapons in 1968 as Alabama Gov. George Wallace’s running mate has one of them so clearly demonstrated the point.

When Wallace announced his choice, LeMay unleashed a riff that included his observation that nukes were “just another weapon in the arsenal.” He went on, saying “I don’t believe the world would end if we exploded a nuclear weapon.” He said he saw no difference between being killed by one or by “a rusty knife,” and “if I had a choice I’d rather be killed by a nuclear weapon.”

In that weird episode, the political damage was minor because Wallace had little chance of being elected. Clark’s remarks on the other hand were akin to throwing McCain a life preserver, in elevating his famous Vietnam service as a long-term prisoner of war as a badge of honor and an election issue.

What’s more, the Clark outburst came at precisely the time Obama, hounded by rumors and questions of his own patriotism, had felt obliged to defend himself, as he previously had been moved to confront allegations arising from anti-American tirades by his former Chicago pastor.

Obama was quick to denounce Clark’s diminution of McCain’s military service as a qualification for the White House, repeating his oft-expressed admiration for McCain’s service and sacrifices. But the general’s untimely comment intruded on Obama’s efforts to reinforce his own record of allegiance to the country in which a man of mixed racial heritage could rise to such political heights.

The perceived need of Obama to defend his own patriotism stems from the repeated false Internet rumors that the Illinois senator with a foreign-sounding name but a practicing Christian, is really a Muslim raised in early childhood in an exotic foreign land (Indonesia).

Obama recently cited the imperative of combating such attacks on him in explaining his decision to reject limited federal money for the general-election campaign. He will need more funds to get the job done, he said, against Republican smear campaigns of the sort that surfaced in 2004 against Democratic nominee John Kerry.

Kerry’s patriotism was severely challenged by a group called “Swift Boat Veterans for Truth,” which insisted that the decorated Vietnam Navy veteran’s service as a small-boat commander did not warrant the medals awarded him. After leaving Vietnam, Kerry became a leader in the anti-war movement.

Obama, in calling Monday for an end to campaign attacks on the issue of patriotism, asserted that “the question of who is, or is not, a patriot all too often poisons our political debate.” But in the context of the continuing war in Iraq, the debate inevitably raises the matter. President Bush questions the patriotism of congressional Democrats who oppose its funding even as American troops are in harm’s way.

As long as Obama calls for their withdrawal, and McCain maintains his support of the Bush policy in Iraq, the issue of patriotism is certain to remain on the campaign agenda. And when opposition to the war is narrowly challenged in those terms, playing the patriotism card may remain the Republicans’ best trump.

Jules Witcover’s latest book, on the Nixon-Agnew relationship, “Very Strange Bedfellows,” has just been published by Public Affairs Press. You can respond to this column at juleswitcover(at)earthlink.net.