Published: Jan 07, 2012 4:26 PM EST

PAUL WISEMAN/AP Economics Writer

WASHINGTON (AP) - Unemployment is higher than it's been going into any election year since World War II.

But history shows that's not likely to stop President Barack Obama from reclaiming the White House.

Presidents can get re-elected even when unemployment is high - so long as it's falling.

Going back to 1956 no incumbent president has lost when unemployment fell over the two years leading up to the election. And none has won when it rose.

The picture is similar in the 12 months before presidential elections: Only one (Gerald Ford in 1976) of nine incumbent presidents lost when unemployment fell over that year, and only one (Dwight Eisenhower in 1956) was re-elected when it rose.

Those precedents bode well for Obama. Unemployment was 9.8 percent in November 2010, two years before voters decide whether Obama gets to stay in the White House. It was down to 8.7 percent in November 2011, a year before the vote. It fell to 8.5 percent in December and is expected to fall further by Election Day.

Obama can perhaps take comfort in President Ronald Reagan's experience. In November 1982, the economy was in the last month of a deep recession, and unemployment was 10.8 percent, the highest since the Great Depression. A year later, unemployment was down but still high at 8.5 percent. By November 1984, unemployment had dropped to 7.2 percent, the economy was rebounding and Reagan was re-elected that month in a 59-41 percent landslide.

"A sense that things are on the mend is really important to people," says Andrew Kohut, president of the Pew Research Center. The trend holds up even when the changes in unemployment are slight. President Bill Clinton was re-elected handily even though the unemployment rate was only 0.2 percentage points lower in November 1996 than it had been two years earlier and was the same as it had been a year before.

Under Obama, unemployment peaked at 10 percent in October 2009, nine months into his presidency, before coming down in fits and starts. Along the way it stayed above 9 percent for an unprecedented 21 straight months.

But unemployment has now dropped four months in a row. And the economy added 1.6 million jobs in 2011, the most since 2006.

Of course, unemployment isn't everything.

Obama's prospects could be changed by the strengths or weaknesses of whoever emerges as his Republican opponent or by a triumph or setback in foreign policy, perhaps in Afghanistan or the Middle East.

Eisenhower no doubt benefited from having an opponent, the high-brow former Illinois Gov. Adlai Stevenson, who had trouble connecting with ordinary voters. Ford may have been sunk by his unpopular decision to pardon former President Richard Nixon. President Jimmy Carter's prospects were surely dimmed by a hostage crisis in Iran - and a failed attempt to end it with a military rescue.

The third-party candidacy of billionaire Ross Perot - not just an increase in unemployment - may have torpedoed President George H.W. Bush's re-election campaign in 1992 by dividing his supporters and giving an edge to challenger Clinton.

And there's no guarantee that unemployment will continue to slide through Election Day. "We've seen this before ... periods when it seemed like things were getting better only to see them grind to a halt," says John Challenger, CEO of the staffing company Challenger, Gray & Christmas. "I'm not yet convinced."

The economists AP surveyed in December see an 18 percent chance that Europe's debt crisis will cause the U.S. economy to slip back into recession. If 2012 brings a recession, Obama would surely lose, writes Yale University's Ray Fair, who feeds economic forecasts into a computer model to predict elections.

Pew's Kohut also warns that voters are wary after seeing the economy fail repeatedly to achieve liftoff two and a half years after the Great Recession officially ended in June 2009. "The public is going to be in a show-me mood," he says.

Still, the online betting market Intrade on Friday put the chances of an Obama victory in November at 52.5 percent.

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