Barack Obama has touched the untouchable in the left-wing narrative of the sixties. He has reminded us and reproached us for how smitten we were with the very idea of revolution. Did we not -- or, at least, very many of us -- cheer on the victory of the Viet Cong and the North Vietnamese in the struggle for Indo-China? Did we ever really ponder the human calamity that followed their triumph in Vietnam and that of their allies in Laos and Cambodia?  Did we even examine the mass cruelties of the Chinese "cultural revolution" that accompanied what we preferred to think of as a peasants' war against America?

No, Obama did not literally ask these questions. But he recalled for us their equivalent, what he himself, being too young, had not experienced, the validating of the charge that the Vietnam opposition was bit short on patriotism. Here is Obama speaking: "by burning flags, by blaming America for all that was wrong with the world, and perhaps most tragically by failing to honor those veterans coming home from Vietnam, something that remains a national shame to this day." Read about this speech in an article by Jonathan Weisman on the web-site of the Washington Post.

Frankly, I do not recall a major Democrat brave enough to utter this reproach to his own supporters. Obama did this in the context of a reproach to the Republican opposition which makes it a habit to question the patriotism of others, as G.O.P. operatives and their subterranean allies have questioned his.  

But there is another context to these remarks, discussed today by Ben Smith in Politico and by Brian Knowlton in the New York Times. Apparently, "leftist blogs" have attacked John McCain as being guilty of "war crimes for bombing targets in Hanoi in the 1960s and castigated him for his coerced participation in (North Vietnamese) propaganda films." A double whammy, so to speak. I wonder if these bloggers now reproach Jane Fonda and Tom Hayden for doing such cheesey film work as volunteers.

In any case, Obama has, with the elegance and eloquence which comes naturally to him, also decried these allegations against McCain. One of Obama's supporters, Gen. (Ret.) Wesley Clark, who thought he could get the Democratic nomination four years just on his military record, derided McCain's military career as anything of a qualification for the presidency. Obama distanced himself from Clark and praised those "who have endured physical torment in service to our country."

"No further proof of such sacrifice is necessary," Obama added.  "And let me also add that no should ever devalue their service, especially for the sake of a political campaign, and that goes for supporters on both sides."