The President: Paying the Price . . .

There is one explanation for Bush's preemptory posture: He genuinely believed that the weapons were there and that the transition to democracy in Iraq would be much easier than it turned out to be. I've been told by people inside the administration that the war's staunchest supporters really did have an optimistic view of this venture -- too optimistic, as it turns out, given the lack of planning for the alternatives. This could explain why Bush decided to place his bet without any insurance. He really did expect to be floating to reelection as morning came to America and Iraq and was about to dawn on that entity Bush likes to describe as "the greater Middle East."

Bush struggled this week to keep that hope alive. In his speech to the nation on Monday, he desperately tried to recreate the world of late 2001 and 2002. He recalled our sense of national unity after 9/11. He reminded us of the victory over the Taliban and "a totalitarian political ideology." He tried, again, to make the case that the war in Iraq is closely linked to the war on terrorism -- he used the words "terror," "terrorist" and "terrorism" 19 times.

But by reminding us of how united we once were, Bush only underscored how divided we have become. And that is why a president who once soared in the polls now finds himself struggling for reelection -- less by touting his own achievements than by trashing his opponent. John Kerry has spent nearly 20 years in the Senate, so there are thousands of votes to go after, a lot of opportunities to say Kerry has flip-flopped, changed his views, done what's necessary to win election.

All this might have worked in normal circumstances, and maybe it will this time. But at the moment, Bush is losing support among independent voters and has not nailed down moderate or even moderately conservative Republicans. Bush has signaled his own weakness by buying time on the Golf Channel, more a home to Republicans than to swing voters (except, perhaps, where the game itself is concerned).

By failing to embrace his opportunity to be a president of national unity, Bush has endangered the great project of his presidency: remaking Iraq. And he has offered Kerry the chance to be as tough as Howard Dean was -- but in the name of uniting Americans at a moment when solidarity is desperately needed.

This is why Kerry has reason to hope that his identity as a Vietnam veteran can trump his history as a Massachusetts liberal. And it's why President Bush, lacking the political insurance he should have sought, is right to be running scared.

Author's e-mail: postchat@aol.com

E.J. Dionne is a Washington Post columnist, a senior fellow at the Brookings Institution and a professor at the Georgetown Public Policy Institute. This article is based, in part, on his just-published book, "Stand Up Fight Back" (Simon & Schuster).