Could these events beyond campaign control jolt race?
ST. PAUL, Minn. - An election-eve terrorist strike. A tanking stock market. A stunner of a jobs report. An unscripted moment.
Democratic President Barack Obama and Republican rival Mitt Romney are on guard for anything that could push the presidential race from its taut course. An autumn surprise is just that, making most late-breaking events tough to plan for.
"You can't overestimate how much the campaigns are sort of on autopilot. In some ways they're incredibly brain dead. They've got a plan, and they are now going to execute it," said Carter Eskew, a top strategist for Democrat Al Gore during a 2000 campaign that came up just short. "They basically trust that they have the system in place to deal with a crisis as best they can."
Late twists in a campaign take on many forms: a verbal stumble that reinforces an existing weak point, a brewing scandal where the murkiness can be as bad as the allegation, a foreign policy crisis few saw coming. Old scars can face fresh examination. Purported bombshells can turn out to be duds.
So the candidates need to be ready for anything.
A look at some possible events that could shake up the race.
As numbers go, keep one eye on the polls and the other on the Dow.
The stock market is naturally volatile, but big swings have been known to alter races. Four years ago, a skidding Dow Jones Industrial Average caused widespread panic about a seizing economy and proved damaging to GOP nominee John McCain, whose party held the White House at the time. On one September day alone, the index fell 778 points for a drop in market value of more than $1 trillion. Three more steep drops followed in October.
In the past couple of weeks, concern about a fragile U.S. recovery and worries about economic conditions in Europe sent the markets down noticeably.
The Dow closed just below 8,000 on Obama's Inauguration Day, Jan. 20, 2009. It now tops 13,000.
Romney has pinned his campaign on the idea that Obama has failed to fix the economy and left too many people without work.
Throughout Obama's term, a high unemployment rate and joblessness caused plenty of consternation. He finally caught some good news in October, when the unemployment rate dropped to 7.8 percent - below 8 percent for the first time in his presidency - as employers added 114,000 the month before.
The last jobs report before the election will be released Nov. 2, a week from Friday.
Democrats worry that even a small tick upward would have a psychological impact on fence-sitting voters anxious for clues about where the country is headed. Another notable drop in the rate could take steam out of Romney's argument.
Economists and investors are already warning of a slowdown in Europe and Asia and that matters because, in an interconnected world, U.S. companies could retract if their business prospects outside the U.S. look weak.
Europe has been a major source of problems, with several countries adopting harsh austerity measures or requiring massive loans to keep economic disaster at bay. A loan default here or a violent protest there could send shudders across the Atlantic Ocean.
Who would have guessed Libya would turn into such a fall flashpoint?
But the Sept. 11 killing of four Americans, including U.S. Ambassador Chris Stevens, served as a stark reminder that the long fight against terrorism is far from over.
Late in the 2004 race, Osama bin Laden released a video threatening more attacks on the United States. It caused some clenching by the electorate, with many late-breaking voters deciding to stick with Republican President George W. Bush and a terror policy they knew. Democratic nominee John Kerry later conceded the video altered the dynamics of the final week of the race.