Mr. McCain’s record on Iraq is far worse than Mrs. Clinton’s. He didn’t just cast a vote but was a drumbeater for the propaganda Mr. McClellan cites, including the neocon fantasies of a newly democratic Middle East. On “Hardball” and “Meet the Press” in March 2003, Mr. McCain invoked that argument, along with the promise that Americans would be “welcomed as liberators,” to assert the war would be “one of the best things that’s happened to America.”

To cover up these poor judgments now  and questionable actions, including his public boosting of Ahmad Chalabi, then a lobbying client of the current McCain campaign guru, Charles Black  Mr. McCain is hoping that the “liberal media” will once again be complicit enablers. We’ll see. He’s also counting on the press to let him blur his record by accentuating his subsequent criticism of the war’s execution  as if the war’s execution (also criticized by countless Democrats), not its conception, was the fatal error.

His other tactic is to try to create a smoke screen by smearing Barack Obama as unpatriotic. Mr. McCain has suggested that the Democratic front-runner is the Hamas candidate and has piled on to Mr. Bush’s effort to slur Mr. Obama as an apostle of “appeasement.” A campaign ad presented Mr. McCain as “the American president Americans have been waiting for” (not to be confused, presumably, with the un-American president Al Qaeda has been waiting for).

Now Mr. McCain is chastising Mr. Obama for not having visited Iraq since 2006  a questionable strategy, you’d think, given that Mr. McCain’s own propagandistic visit to a “safe” Baghdad market is one of his biggest embarrassments. Then again, in his frantic efforts to explain why he sided with Mr. Bush to oppose an expanded G.I. bill that the Senate passed by 75 to 22, Mr. McCain has attacked Mr. Obama for not enlisting in the military.

Besides making Mr. McCain look ever angrier next to his serene opponent, this eruption raises the question of why he chose double-standard partisanship over principle by not applying this criterion to the blunderers who took us into Iraq. Unlike Mr. Obama, who was 7 years old in 1968, Mr. Bush and company could have served in Vietnam as Mr. McCain did.

The McCain campaign may have no choice but to double down on Iraq  what other issue does the candidate have?  but it can’t count on smear tactics or journalistic and public amnesia to indefinitely enforce the McCain narrative. As the McClellan circus shows, unexpected bombshells will keep intervening  detonating not only on the ground in Iraq but also in Washington, where more Bush alumni with reputations to salvage may yet run for cover about what went down in 2002-3.

As F. Scott Fitzgerald would have it, we will be borne back ceaselessly into the past. Or so we will be as long as Americans continue to die in Iraq and as long as politicians like Mr. Bush, Mr. McCain and Mrs. Clinton refuse to accept responsibility for their roles, major and minor, in abetting this national tragedy.