Presidential debates are a little like watching Olympic figure skating. The debaters are out there all alone on the ice with four or five hair-raising political jumps to execute. Political junkies sit glued to their sets holding their breath as the candidates leap, sometimes into thin air, to score points against the opponent while trying to avoid mistakes that could cost them the competition.

[IMGCAP(1)] Forty-eight hours from now, President Bush and Sen. John Kerry (D-Mass.) will take to the ice, but Kerry goes into these important debates at a decided disadvantage — behind in the polls and saddled with an inconsistent Iraq policy that has undermined his credibility. Last week, as the campaign clock ticked down toward these crucial debates, Kerry continued his unbroken and inexplicable string of Iraq flip-flops with a pair of major foreign policy addresses.

The ever-changing Kerry did yet another 180-degree turnaround on his Iraq policy, this time morphing into Howard Dean and assuming the mantle of the anti-war candidate. Using some of his harshest words to date to assault the president’s anti-terror policies, Kerry called the Iraq war “a profound diversion” from the battle against al Qaeda while conveniently ignoring his own vote in favor of that “profound diversion.”

He laid out his “plan” to fight a “smarter, more effective war on terror” that looked remarkably like the plan the Bush administration is already implementing, although, according to Kerry, he would do it faster, better, more decisively and because of his diplomatic skills and personal charm, with more allies.

Yet that same week, in an unprecedented attack, Kerry assailed the integrity of America’s staunchest ally in Iraq, its courageous prime minister, only moments after Ayad Allawi’s address to Congress on progress in the war.

Kerry spokesman Joe Lockhart made the malicious attack personal, going so far as to call the prime minister “a puppet” of the Bush administration and claiming “you can almost see the hand underneath the shirt today moving the lips.” So much for the diplomacy of Kerry.

With his poll numbers stalled, perhaps Kerry simply decided to roll the dice — adopt yet another position on the war on terror and hope that the debates will give him the opportunity, in all likelihood his last opportunity, to win over decidedly wary voters. That’s a pretty big gamble if history is any indicator.

Few candidates have actually won debates. Ronald Reagan’s performances against Jimmy Carter, and four years later against Walter Mondale, are the exception. More often, presidential candidates lose debates. Gerald Ford’s “free Poland” gaffe in 1976; Michael Dukakis’ lame response to a hypothetical question about the death penalty in 1988; George H.W. Bush’s ill-timed glance at his watch in 1992; and Gore’s childish behavior in 2000 were all examples of how to lose a debate.

That is the dilemma facing Kerry. Given the poll numbers, Bush needs to assert his leadership, remind voters of his record of strength and trust, and lay out what he hopes to accomplish in another term. Most of all, however, he needs to avoid a mistake. A draw is a win for Bush.

Kerry, on the other hand, needs to win decisively. To do that, he must overcome a sizeable credibility gap. Voters are already leery of a candidate who refuses to take clear stands on issues and is seen as vacillating on everything from the war in Iraq to education reform.

With time running out, Kerry must use the debates to try to draw contrasts with Bush, but the negative image his inconsistency has fostered will make this difficult. If he attacks with the harsh tone that he uses day in and day out in campaign appearances, he risks taking on more than Dean’s anti-war stance. He could also come across as an unpleasant attack dog with little positive to say, and he can ill afford any more negatives.

So Kerry is facing a tough challenge. He wants to attack Bush’s integrity and competence on a range of issues, particularly on the war on terror, but he must do it without appearing to attack. Not easy to accomplish, especially for a candidate whose day-to-day campaign rhetoric has been extremely negative and often personal.

Nor will Kerry’s 20-year Senate voting record on defense issues or his recent record of flip-flops on Iraq be easy to defend. When your record cannot bear scrutiny, you have little choice but to attempt to put your opponent on the defensive by any means necessary.

So, I suspect, Kerry’s strategy will be based on one line that Kerry can’t wait to deliver and Bush must be ready to rebut. “Mr. President, stop questioning my patriotism.”

You heard it here first, though Kerry and his debate coaches have, no doubt, spent weeks devising ways to use the line and variations of it over and over again. Raising Kerry’s voting record and past statements, of course, has nothing to do with patriotism and everything to do with judgment — what choosing a president, at its core, is all about. Who has the wisdom and common sense to lead and a consistent record that voters can believe? That is what this debate comes down to — that and not making mistakes.

David Winston is president of The Winston Group, a Republican polling firm.