Can it really be this close, again?

Four years after a disputed election that left the nation bitterly and almost evenly divided, Americans return to the polls Tuesday facing yet another excruciatingly tight contest that could defy history by once again coming down to a handful of votes in a few key states.

Despite the longest and most expensive campaign in US politics, and an election cycle that has included a number of dramatic events - including the Sept. 11 terrorist attacks, the Iraq war, and an economic recession - neither President Bush nor Sen. John Kerry appears to have gained any discernible edge among an electorate that looks as stubbornly fixed as it did in 2000.

The closeness of the race is particularly unusual, given that campaigns involving sitting presidents almost always play out as a referendum on the incumbent's record - with the public typically coming down on one side or the other by sizable margins. But this year, reactions to Mr. Bush's tenure remain as polarized as the electorate itself, with Republicans giving him astronomically high approval ratings, and Democrats offering equally sharp levels of disapproval. Opinion is likewise split over which issues are most important, with some voters citing terrorism and the Iraq war, and others pointing to domestic issues such as jobs and healthcare.

Of course, that calculus could change. Strategists on both sides speculate that current polls may be missing a possible surge in turnout among, say, young voters, or white evangelicals, that could tip the results decisively - and even herald a new period of dominance for one party or the other.

But for now, with the race still too close to call, the nation's partisan divide not only appears to have endured but, if anything, seems to be intensifying in the face of pressing national issues and a presidential contest that 8 in 10 voters agree is of great importance, according to a new poll by the Pew Research Center.

"Anybody who tells you they can make a prediction based on these polls is overly creative," says GOP strategist Charlie Black. "I think the fact that we're in crisis and at war just means intense interest on both sides."

In some ways, a backdrop of crisis seems to have left the electorate conflicted between a desire for change and a fear of it. Both candidates have been trying to push those emotions one way or the other, with Bush arguing that it's risky to change horses midstream, and Kerry making the case for a "fresh start." But so far, neither argument appears to have won out.

Some analysts suggest that polls may also be misrepresenting the strength of the public's desire for change - because voters may not want to admit that they oppose the president's policies.

"When you're in a time of crisis or war, as we are, voters are very reluctant to say they'll oppose a sitting president. It's a slur on their patriotism," says presidential historian Robert Dallek. But, he adds, "What really determines the outcome of these elections involving an incumbent is the incumbent's record." To Mr. Dallek, that means "Bush will lose because his record, both domestically and in foreign affairs, is pretty questionable."

For weeks, Bush has straddled the dividing line between safety and danger for an incumbent, with his approval ratings hovering just below 50 percent. But analysts note that Kerry has not managed to gain a clear majority of support, either.

"[Kerry]'s doing very well among his partisans, and poorly on the other side," says Eric Rademacher, a pollster at the University of Cincinnati in Ohio. The contest remains unusually tight because "both Bush and Kerry are doing fairly well among independents, and the electorate is so balanced between them."

It's still possible that remaining undecided voters could sway the election by backing one candidate or the other overwhelmingly. Both campaigns argue they will draw more support from undecideds in the end, though typically those voters tend to break against the incumbent.

But in general, this is a race that has been marked by stability - and proved almost impervious to events, as reflected in the almost total lack of reaction in polls this weekend to the tape released by Osama bin Laden. Indeed, an NBC/Wall Street Journal poll found that 69 percent of voters said they made up their minds before the summer's political conventions.

As a result, the election may come down to turnout, with both campaigns working furiously to get supporters to the polls in a handful of closely contested states - including Ohio, Florida, Pennsylvania, Wisconsin, Michigan and Iowa. Both candidates spent their final full day of the race making tarmac-to-tarmac stops in these battlegrounds, including appearances three blocks apart in Milwaukee.

The biggest wild card is the number of newly registered voters in these states: Analysts say it remains unclear how many of them will turn out, and which candidate they'll support.