To these ideological concerns, conservatives quietly add the "temperament issue." McCain's coiled intensity is prone to sudden release. Even his strongest supporters must feel the same thrill as camping on the side of an active volcano.

Being avuncular is not a constitutional requirement to be president, as Andrew Jackson demonstrated by fighting 103 duels that left two bullets lodged in his body. But Franklin Roosevelt and Ronald Reagan created an expectation of presidential geniality. McCain, in contrast, is all sharp, jutting angles -- a work of cubism in a nation that favors watercolors.

Ultimately, however, judgment matters more than temperament in a president. And stepping back a moment from the past few years, McCain's judgment on the big issues deserves grudging respect from conservatives.

McCain has been right about the conduct of the Iraq war. During the senator's first trip to Iraq in August of 2003, a British colonel in Basra warned him that the start of a major insurgency was weeks away. American military leaders, McCain realized, were putting in place a modified Westmoreland strategy -- a war of attrition against the enemy while training friendly forces -- that he had seen before in Vietnam and seen fail. So he spent several months as a voice in the wilderness, calling for more troops and a more aggressive counterinsurgency strategy. Not since Churchill's wilderness years has a leader been more relentlessly vindicated by events, which culminated in the replacement of the leadership of the Pentagon and the adoption of McCain's approach.

McCain has been right on the issue of torture. Every responsible member of Congress recognizes the need for interrogation techniques for terrorists beyond asking name, rank and serial number. But McCain has argued that extreme techniques such as waterboarding should not be the American norm. He embraces an American exceptionalism: that we distinguish ourselves from our enemies by how we treat our enemies. And his argument has a unique power because of his own story. The victims of torture in North Vietnamese camps sustained their sanity, in part, by knowing they would never do the same to their torturers. McCain's concern on this issue has never been primarily its effect on public diplomacy. But there is no question that an early, public, decisive act of self-limitation would have helped to clarify the American cause in the world.