No Democrat has tacked closer to the political winds on the war in Iraq than presidential contender John Edwards, whose lack of constancy is so transparently a matter of political calculation as to be appalling.

As a senator, Edwards voted to authorize military action in 2002 — based, as all now know, on specious intelligence. He declared, "Saddam Hussein's regime is a grave threat to America and our allies — including our vital ally, Israel."

In 2004, after the lack of weapons of mass destruction was well known, Edwards — then John Kerry's running mate — stuck by his vote, telling Tim Russert of NBC News: "It was the right thing to do to give the president the authority to confront Saddam Hussein."

Then, in 2005, eying a run for the White House, Edwards declared bluntly, "I was wrong." Now, he presents his flip-floppery as a mark of moral courage while calling for withdrawing the troops.

But last week on "Meet the Press," Russert grilled Edwards again, asking him to explain why he had maintained strong support for the war in 2004.

The candidate offered a stunning rationale: He "was in the middle of a very intense campaign" that was "very important for America," suggesting he was either too busy to figure out the central issue before the nation — or, perhaps, too political.

It was only after the campaign — when his wife, Edwards cheesily noted, was diagnosed with breast cancer, that "for the first time, I had time to really think about, No. 1, what I was going to spend my time doing, and, No. 2, my vote for this war and, over time, when I reflected on what I thought was going to be necessary, going forward, to have some moral foundation to work on issues like poverty and genocide and things that I care deeply about, I could no longer defend this vote. It was pretty simple."

What's simple is this: The poll movements and the demonstrated impossibility of getting elected as a Democratic hawk — witness the pressure on Sen. Hillary Clinton and the political excommunication of Sen. Joe Lieberman — are what changed Edwards' mind. Not events on the ground.