What a difference a couple of weeks make. Polling during and just after the Republican National Convention, Time and Newsweek have George W. Bush ahead of John Kerry 52 to 41 percent. Post-convention polls show Bush ahead 52 to 45 percent (CNN/ USA Today /Gallup), 49 to 42 percent (CBS), 47 to 43 percent (Fox News), and 52 to 43 percent (ABC/ Washington Post ). Post-convention polls in battleground states show similar results. Gallup shows Bush up 14 points in Missouri and 9 in Ohio, states he carried by 2 and 4 points, respectively, in 2000, and up 1 in Pennsylvania, which he lost by more than 4 points. Kerry is off the air in the battleground states of Missouri, Arizona, Arkansas, and Louisiana. It's too soon to say that this is the last sharp shift in the two candidates' standings. But it is a bigger shift than we have seen since John Kerry clinched the Democratic nomination on March 2.

The reaction of the Bush campaign is that people are finally listening as the president makes his case--and watching John Kerry flounder in the month after his convention. Bush's plan is to keep on keeping on and hope the unprecedented Republican turnout effort matches the turnout drives run by unions and Democratic 527 organizations. The reaction of the Kerry campaign is that its candidate was hurt by his failure to respond aggressively enough to the Swift Boat Veterans for Truth ads and that he needs to fight back harder. Democrats like Susan Estrich, Michael Dukakis's campaign manager in 1988, see a replay of that year and call for attacks on George W. Bush's attendance record in the Texas National Guard--helpfully provided by sympathetic old media last week.

But this misdiagnoses Kerry's problem. Dukakis was hurt because it was pointed out that for 11 years he supported weekend furloughs for prisoners sentenced to life without parole--a policy for which there is no rational argument. Kerry was hurt because at least some of the SBVT charges proved true. On August 11, his spokesman admitted that he was not on an illegal mission in Cambodia at Christmastime 1968--the memory of which, he said on the Senate floor in 1986, was "seared--seared--in me." His campaign left uncorroborated his frequent claims to have been on secret missions to Cambodia at other times. He has not authorized release of his military records. As this is written, Kerry has not taken questions from the press since August 1. Sometimes there is no good defense, and the only thing you can do is try to change the subject.

With his friends. The problem for Kerry is that when he tries to change the subject, he seems to change his position. This is partly out of the typical politician's temperament: "Some of my friends are for the bill, and some of my friends are against the bill, and I'm always with my friends." But it also arises because the Democratic constituency that Kerry must rally to vote on Election Day and before (voting starts in Iowa September 23) is deeply split on issues like Iraq. Many think we should leave now. Others think we should persevere. Kerry is with his friends.

In an August back-and-forth, Bush got Kerry to say that, knowing what he does today, he still would have voted for the Iraq war resolution. Then last week he said it was "the wrong war, in the wrong place, at the wrong time" --though he had condemned a similar statement made by Howard Dean last December. On August 1, he said he would consider redeploying troops from Germany and South Korea. When Bush announced such deployments on August 16, Kerry denounced them. His latest line is to say that the $200 billion spent or to be spent on the Iraq war should have been spent on domestic needs. As a Democratic consultant once told me when I asked about an opponent's moves, "I'm puzzled by his strategy."

Puzzling as well is the Democrats' notion that attacking Bush's National Guard service is going to break the campaign wide open. Haven't they been watching the $60 million worth of anti-Bush ads the Democratic 527s have been running since March? Bush withstood that onslaught and stands, apparently, a little ahead. There's no guarantee he'll still be there after the debates or on Election Day. But, for the first time since January, it wouldn't require a sharp shift in opinion.

This article was published by U.S. News & World Report