If John Kerry loses this election, August will be seen as the time when he did. But if Kerry wins, it will be because the last month set up the circumstances for his triumph. And as Bill Clinton probably told the Democratic nominee in that pep talk from his hospital room over the weekend, the way the story turns out is, in significant measure, under John Kerry's control. Democrats outside the Kerry campaign have been in a grumpy, jumpy mood since the oxymoronically named Swift Boat Veterans for Truth pushed the media into a frenzy over what Kerry did and didn't do in Vietnam. The month of August was miserable for Kerry and Bush's post-convention bounce has left members of Kerry's party even more depressed.

It's always a bad sign for a campaign when the media run stories about impending campaign shakeups, usually in accounts full of disparaging quotations from (often anonymous) party leaders.

The Kerry campaign was sufficiently worried about all the bad tidings that it dispatched some of its top officials to New York last Thursday to insist that things were under control, claims usually seen as a sign that they're not. They did admit, though, to underestimating the trouble the Swift boat crowd had caused.

In fact, the anti-Kerry ads fit so neatly with the Republican Convention's goal of painting Kerry as soft on defense and not tough enough to deal with terrorism that it becomes ever harder to believe the Bush campaign's denials of any involvement with the Swift boat group.

In any case, Republicans savored a month in which almost all the campaign coverage was about national security in the abstract, and questions about Kerry's service in particular. Better that for Bush than, say, questions about his strategy in Iraq, or his approach to jobs and health care. And all this was happening while Kerry bought almost no television advertising, saving his cash for the fall.

So how could such a terrible month be a setup for a Kerry victory?

The answer lies in the word "overkill." If there is one thing that came through from last week's convention, it is that Republicans knew that Bush could not win on his own record alone. They had to frighten the country about Kerry and were willing to say anything -- to distort Kerry's record and to lie about it if necessary -- to further that end.

Kerry's use of his Vietnam experience to prove that he is tough enough to be president has not been enough to counter those attacks. But the Republicans' tactics have presented Kerry with a timely opportunity to show his steel. Voters are about to learn whether he is strong enough to stand up to President Bush and his slash-and-burn surrogates. If Kerry can face down Bush's withering attacks, the very act of campaigning becomes a way of passing the toughness test that Bush has put before him.

There is a great advantage in politics to the candidate who is seen as fighting against attacks rather than launching them. "The other side," top Kerry strategist Tad Devine said hopefully, "has opened the door so much for us that we are in a very strong position to counterpunch." Devine's comments suggest that Kerry's campaign is about to get a lot more aggressive -- and none too soon in the eyes of worried Democrats, including Clinton.

But Kerry needs more than defense. Many Democrats believed a month ago that Kerry might win simply because of widespread public frustration with Bush. But as one (yes, anonymous) Democratic consultant not connected to the Kerry campaign put it: "Not being Bush is not enough." Kerry's views were easily parodied by Republicans in New York because, this consultant said, voters are still not clear as to what Kerry would do for them.

So Kerry has three battles to wage. He has to fight Bush and his attacks. After all that was said about him at the Republican convention, you would think that Kerry has all the incentives he needs. He has to show voters what he is fighting for. And he has to reassure an anxious party that he has a plan to be back in the thick of things by the beginning of October.

Complacency hurt the Kerry forces in August. Democrats cannot afford panic in September. No one knows that better than the Comeback Kid, who has climbed out of much deeper holes than the one Kerry is in now -- and who was not about to let a little heart surgery get in the way of passing along the message.