Conventional wisdom among Democratic strategists has been that sooner or later national security will recede as a concern and bread-and-butter domestic issues will decide the presidential election. One senior party operative recently offered what he called the Google theory of 2004: If an Internet search about the campaign the day after the election turns up more references to Iraq than to the economy, that probably means President Bush has won.
But the continuing violence in Iraq is shaking these assumptions. It's no longer certain that domestic issues such as jobs and healthcare will displace Iraq as the central focus of public attention and the campaign debate. Nor is it certain that sustained attention on Iraq will benefit the president.
This transformed landscape will challenge both Bush and his Democratic opponent, Sen. John F. Kerry of Massachusetts.
The dangers for Bush are most obvious. Iraq is his war. Bob Woodward, in "Plan of Attack," his extraordinary new book on the administration's march to the invasion, describes Vice President Dick Cheney as "a powerful, steamrolling force" for war.
Bush emerges from Woodward's portrayal as more veiled and even inscrutable. Yet Bush's determination to invade Iraq and depose Saddam Hussein seems just as unshakeable as Cheney's. In this telling, it is Bush, more than any advisor, who drives the country to war.
And it is Bush who has the most at stake in the outcome. Recent polls show some evidence of the nation rallying around the commander in chief, as it often does when U.S. troops are under fire.
But as the death toll mounts -- April was the deadliest month for American troops -- so do doubts about Bush's strategy for stabilizing and securing Iraq.
A CBS/New York Times survey released last week showed that approval of Bush's handling of the war plummeted to 41%, dragging his overall approval rating below the 50% level that historically marks the dividing line between presidents who win reelection and those who don't.
Those numbers are certain to fluctuate in the months ahead. Yet they underscore the threat to the president. The centerpiece in his case for reelection is that he has been a resolute and effective manager in the war on terrorism. His signature contribution to that war has been the invasion of Iraq. Last week's poll numbers suggest that if Americans come to see that decision as misguided, or the occupation as failing, the central arch of Bush's support could erode.