As the presidential candidates enter Friday night's critical second debate, they are appealing to a competing set of impulses among voters - the more dominant of which may ultimately determine the outcome of the election: a sense of resolve vs. a desire for change.
Throughout the campaign, polls have indicated that voters are unhappy with the direction of the country, a dynamic that has often portended the ousting of an incumbent and that remains Sen. John Kerry's biggest advantage. But in a time of war and threat, voters are also more inclined to rally around their leader and regard change as a risky proposition, a sentiment President Bush has worked to exploit.
Until recently, Mr. Bush seemed to have gained the upper hand in this battle, muting voters' desire for change by casting Senator Kerry as an unsuitable alternative - an overly political "flip-flopper" who would be weak on defense.
But in the wake of last week's debate, with polls showing the race once again tied, Kerry seems to be gaining new traction with his calls for a fresh start. Analysts say two things have happened to aid that shift: The debate put the campaign's focus squarely back onto Bush's record. And Bush's attacks on Kerry as a flip-flopper may have lost some of their bite, since viewers watched the Massachusetts senator give a steady, composed performance in the 90-minute debate.
"There's a very clear Republican strategy, which is simply [to argue], 'There's no way to change, you just have to tough it out. And we're tougher at toughing it out,' " says Sam Popkin, a political scientist at the University of San Diego. Kerry's task, on the other hand, is to convince voters he's "smart enough to do it another way."
Bush faces more pressure going into Friday night's debate, after garnering poor reviews for his performance last week. On a stylistic level, strategists say he needs to present a warmer, more genial persona, avoiding the peeved and irritated expressions that drew so much attention.
Substantively, while he is likely to continue attacking Kerry, analysts say he needs to broaden his critique, and present a better defense of his own record.
At the same time, even as the president is likely to insist on the need to stay the course in Iraq, some say he must also present his own vision for change - both at home and abroad - so as not to cede that ground to Kerry.
Bush's challenge "is to be as forward-looking as he can be," says Republican strategist Scott Reed. "The questions will be about the past, but after he covers them he needs to pivot to what he's going to do for the next four years."
In contrast, Kerry will again try to cast Bush as either satisfied with the status quo, or not fully aware of people's problems, and continue to press that "there's a need for a new direction and change," adviser Joe Lockhart told reporters.
To some extent, Kerry has often struggled to make the case for change because he has had a hard time distinguishing his position from the president's on Iraq - the issue that has, for the most part, dominated the campaign.
This week, Bush moved to challenge Kerry's claim to be the candidate of change, by arguing that Kerry would not bring significant positive differences in Iraq, but would offer only a weakening of resolve. In a hard-hitting speech in Pennsylvania on Wednesday, Bush argued that Kerry's plan for Iraq "should sound pretty familiar - it's already known as the Bush plan." The only real difference between the two approaches, Bush said, is that Kerry has talked about setting a timetable for withdrawing troops - something that "may satisfy his political needs, but it complicates the essential work we're doing in Iraq."
Yet some strategists argue that Kerry doesn't need to present a dramatically different plan on Iraq, but must simply present himself as a smart and capable leader who could offer a fresh start. When it comes to matters of war, voters tend to look more for reassurance than radical change. But where Kerry can present himself as offering big differences is on domestic issues - such as healthcare and taxes - which are likely to come into sharper focus in this debate and the next.
On Iraq, "people sense that there's enough difference [between Bush and Kerry] without being something that's too radical," says Democratic pollster Paul Maslin. "And on domestic issues, there's huge differences - and those will become more vital over the next month."
A subset to all this is the tussle over which candidate's record is more obviously in the spotlight, with both men hoping that the focus winds up on their opponent. In general, analysts say, races involving sitting presidents tend to revolve around the incumbent's record, particularly as the campaign gets into the final weeks.
But Bush has done an unusually good job at highlighting Kerry's record as well. And this week's vice-presidential debate arguably was focused more on Kerry than on Bush.