WASHINGTON -- It is a tribute to John McCain's remarkable political luck that the issue of his temper should arise just as the Democratic contest has reached a stage of red-faced, ear-steaming mutual contempt. It was former President Bill Clinton, not McCain, who recently lost his cool during a meeting with California superdelegates. In a finger-pointing rage over Gov. Bill Richardson's endorsement of Barack Obama, Clinton claimed, "Five times to my face (Richardson) said that he would never do that." The San Francisco Chronicle reported that one attendee called it "one of the worst political meetings I have ever attended."

All of which undermines the most incendiary point made against McCain. In the course of a recent Washington Post article on McCain's history of anger management issues, former New Hampshire Sen. Robert Smith claims that McCain's "temper would place this country at risk in international affairs, and the world perhaps in danger." The argument seems to be: McCain will get ticked off and invade Iran -- or maybe, on a bad day, Canada. But Bill Clinton's famous purple rages did not translate into foreign policy aggressiveness or irresponsibility. History shows that the petty can be peaceful -- and that men of irenic temperament can be forced to war.

But the McCain campaign's response to the Post article claimed that the candidate's "temper is no greater than the average person's" and that the article is "99 percent fiction."

I'd bet on less than that.

McCain, after all, has contributed to the legend of his own temper -- using it as evidence of his own fierce independence. His 1999 autobiography relates how, as an angry 2-year-old, he would hold his breath until he lost consciousness -- the kind of family lore with the ring of truth. He seems to take pride in the wild defiance of his high school and college years. And McCain's spirited contempt for his captors at the Hanoi Hilton is worthy of legend.

McCain's colleagues in Congress do recount rough treatment. Having worked for years as a Senate staffer, I can report that it is not common for one member to tell another "f--- you" -- as McCain did to Sen. John Cornyn during the immigration debate. And McCain himself, in more reflective moments, understands this weakness. "I have a temper, to state the obvious," he wrote in a 2002 memoir, "which I have tried to control with varying degrees of success because it does not always serve my interest or the public's."

So what difference does this make? Despite these emotional eruptions, McCain has managed to retain a loyal staff and work on legislation across the aisle.

But temperament is not irrelevant in a leader. A pronounced trait such as anger puts a particular burden on a political figure's inner circle of friends and advisers. They can choose to tap the brakes or push the accelerator -- to moderate and channel a leader's tendencies or feed those faults for their own purposes. Aides to Richard Nixon gained favor by stoking his paranoia. Some of Bill Clinton's staff enabled his self-indulgence and recklessness.

In at least one instance, McCain's temper seems to have clouded his judgment. In February 2000, after being criticized by religious conservatives, McCain gave a very angry speech in Virginia attacking leaders of the religious right as "agents of intolerance," comparing them to Louis Farrakhan, accusing them of having "turned good causes into businesses," calling them "corrupting influences on religion and politics" who "shame our faith, our party and our country." It was a tantrum disguised as a campaign event. Key advisers around McCain enflamed this pointless anger instead of dousing it. These days, Sen. Joe Lieberman -- one of the most decent and temperate men in Washington -- apparently is playing the role of McCain's fire marshal.

On the evidence of the Virginia speech, McCain's worst temptation is not anger but moral arrogance. Opponents are not merely wrong; they are venal, self-interested and corrupt. In a righteous cause, McCain can be self-righteous.

But this weakness, as is often the case in politics, is inseparable from McCain's political appeal. Recent weeks have raised the question: Can the detached, intellectual Barack Obama draw clear lines of outrage on the anti-American rhetoric or violent radicalism of some of his associates? When it comes to the largest matters -- public officials who violate the public trust or enemies who threaten America -- no one can accuse McCain of insufficient moral outrage.