If the Bush administration had gone after Osama bin Laden with anything akin to the energy it is expending to discredit Richard Clarke, the story of America’s response to terrorism might have been dramatically different. That, of course, is the point that Clarke, the former White House counterterrorism adviser, makes when he says that Bush and his aides “ignored” the terrorist threats before September 11, 2001, and, even more significantly, when he suggests that the administration diverted attention from the real war on terrorism with an unnecessary war on Iraq.

Those are powerful charges, and Clarke has made them convincingly in his testimony before the National Commission on Terrorist Attacks on the United States, in various media appearances over the past few days, and in his book, Against All Enemies. Predictably, the White House spin machine has been churning out increasingly-visceral attacks on Clarke, a self-described Republican who still praises Bush’s father as a masterful leader. Amid the tit-for-tat that has developed, however, Clarke has already prevailed. No matter what the Bush administration throws at the man who served in four White Houses, Clarke has already trumped his attackers.

Clarke did so by opening his testimony before the commission on Wednesday not with a bold pronouncement about the failings of the administration, but with an apology: “I welcome these hearings because of the opportunity that they provide to the American people to better understand why the tragedy of 9/11 happened and what we must do to prevent a reoccurrence. I also welcome the hearings because it is finally a forum where I can apologize to the loved ones of the victims of 9/11,” he began. “To them who are here in the room, to those who are watching on television, your government failed you, those entrusted with protecting you failed you and I failed you. We tried hard, but that doesn’t matter because we failed. And for that failure, I would ask — once all the facts are out — for your understanding and for your forgiveness.”

In that statement, Clarke proved to be a more masterful political strategist — and, be clear, a duel between a renegade aide and a president in an election year is about politics — than White House electoral strategist Karl Rove. Why? Because Clarke recognized the ultimate vulnerability of the Bush administration: An absolute inability on the part of Bush, Vice President Dick Cheney, Secretary of Defense Donald Rumsfeld and, above all, National Security Advisor Condoleezza Rice, to admit when they have failed, when they have been proven wrong and when they have been caught in lies.

The administration that began by neglecting George Bush’s popular-vote deficit in the 2000 and claiming a mandate for radical change has been consistent in nothing so much as its refusal to accept unpleasant realities. Bush and his aides always refuse to take responsibility for anything that goes wrong. As such, they are always pointing fingers of blame at others. September 11? Blame evil or Bill Clinton — pretty much the same thing in the Bush administration’s collective mind. False information about Iraq’s supposed weapons of mass destruction program gets into the State of the Union Address? Blame the CIA or someone, anyone, in Europe. Economic downturn? Blame Democrats in Congress for not backing bigger tax cuts for corporations and more-of-the-same trade policies. False figures on the cost of Medicare reform go to Congress? Blame, well, er, gee, gay marriage?

No matter what goes wrong, the ironclad rule of the Bush administration has been to find someone outside the administration — preferably a Democrat or a foreigner — to blame. And if there is no way to blame someone else, the policy has been to keep expressing an Orwellian faith in the prospect that the failure will become a success, or that the lie will be made true — witness Cheney’s refusal to back away from his pre-war “they’ll greet us with flowers” fantasy about the Iraqi response to a U.S.-led invasion.

Supposedly, this refusal to bend in the face of reality is smart politics. But a constant pattern of avoiding responsibility tends, eventually, to catch up even with the smartest politicians. Richard Nixon never recognized that fact and it destroyed his presidency. Bill Clinton, for all of his failings, did recognize it and, with his televised apology for mishandling of the Monica Lewinsky mess, thwarted Republican attempts to destroy his presidency.

Richard Clarke, who lived inside the belly of the beast that is the Bush administration, recognizes its many vulnerabilities. And, by reminding the American people that apologies are owed for failings before 9/11 and since, he struck Bush and his aides where they are weakest.