WASHINGTON (AP) - Septembers shock, Octobers surprise, early Novembers can knock a campaign sideways. In a presidential race's waning weeks, almost anything can happen - bedlam in the Middle East, financial panic at home, a scandal in the headlines. And as Election Day ticks closer, candidates get less and less time to absorb the blow.
Sometimes the kind of jolt known as an "October surprise" matters in the end. Other times it doesn't. But every campaign knows enough to worry about what might come.
"A fall general election is a very wild ride," said Steve Schmidt, who managed Sen. John McCain's campaign and served on George W. Bush's re-election team. "It's a volatile ride. You're always on guard."
Often the unforeseen sweeps in from overseas. This week's violent protests at U.S. diplomatic outposts and the armed attacks that killed the ambassador and three other Americans in Benghazi, Libya, grabbed a presidential race focused on the domestic economy and spun it around to foreign policy.
Republican nominee Mitt Romney seized on the unrest in Libya, Egypt and then Yemen to criticize President Barack Obama as a weak world leader willing to appease Islamic extremists. Obama portrayed Romney as untested in foreign policy and rushing to politicize a tragedy before fully understanding the facts.
How much of that is remembered by voters on Nov. 6 will depend on what happens in the meantime. The Arab Spring nations may settle down and other surprises, such as skyrocketing gasoline prices or trouble between Israel and Iran, might emerge and be fresher on voters' minds.
"Every day matters. Every moment changes the needle," said Democratic strategist Donna Brazile, a veteran of the Bill Clinton and Al Gore presidential campaigns. But she thinks it's unlikely a late surprise will reset the race because "the basic threads of this election are already implanted in the minds of voters."
The classic definition of an October surprise - a term popularized by Ronald Reagan in 1980 - is timely news orchestrated by a president to help his own re-election. Now it's more broadly applied to any unexpected development with potential to sway the race toward one candidate or the other.
In 2008, Obama's campaign benefited from the autumn economic shock that, in its aftermath, threatens his re-election.
"Four years ago at this exact hour, John McCain had a lead coming out of a very successful convention. Nobody had any idea a series of events was going to unfold that brought the global financial system to the brink of collapse," Schmidt said Thursday. "It effectively ended the campaign."
On Sept. 15, 2008, Lehman Brothers investment bank filed for the nation's largest bankruptcy ever, setting off a stock market crash and global financial panic that voters largely blamed on the Republicans in power. McCain didn't help his cause by declaring that "the fundamentals of the economy are strong" - a statement mocked by the Obama campaign. That's not to say Obama wouldn't have won, anyway, but it would have been a different race.
The most famous October surprise is one that never happened.
In 1980, Republican challenger Reagan kept suggesting that President Jimmy Carter was trying to time the release of 52 American hostages held by Iran for just before Election Day. It didn't happen.
Instead, Iran freed its hostages just hours after Reagan's inauguration, sparking rumors that his campaign had secretly negotiated with the Iranians to delay the hostages' release. The allegation lingered for years, further cementing the term "October surprise," until it was laid to rest by a bipartisan congressional investigation in 1993.
The idea of the autumn game-changer dates at least to President Lyndon Johnson, who announced a halt to bombing in Vietnam on Oct. 31, 1968, giving a boost to the campaign of Vice President Hubert Humphrey. Richard Nixon won that race anyway. Nixon's 1972 re-election campaign benefited greatly from an October announcement by his national security adviser, Henry Kissinger, that "peace is at hand" in Vietnam, which proved premature.
Other autumn surprises that rocked presidential campaigns:
- Oct. 29, 2004: Osama bin Laden releases a video threatening more attacks unless the U.S. changes its ways.
It was widely reviled as a terrorist calling for Americans to vote against their president, George W. Bush, and instead strengthened the president's campaign. John Kerry would later contend that the video cost him the race. "It changed the entire dynamic of the last five days," Kerry said.
- Oct. 12, 2000: Al-Qaida in Yemen terrorists blow a hole in the USS Cole as it sits in port, killing 17 sailors.
The gut-wrenching shock to the nation didn't have a clear impact on the race between Gore and Bush. Later, a minor November surprise - the revelation that Bush had been arrested on a misdemeanor drunken driving charge back in 1976 - stirred Republican indignation because it came just five days before the election. Voters shrugged it off.
- Oct. 1, 1992: Billionaire Ross Perot, who had impulsively quit his third-party presidential bid in July, jumps back in.
Perot got a spot in the presidential debates alongside President George H.W. Bush and Clinton, leaving them scrambling to respond, and ended up sucking votes from both sides.
"Sometimes it seems that we're at the mercy of events, instead of shaping events," Romney told supporters Wednesday. He was referring to the United States and its role in the world.
The same could be said, however, of presidential campaigns.