Washington (CNN) -- President Barack Obama is running against former Massachusetts Gov. Mitt Romney, but the economy may truly be his greatest opponent.
"It's not the only factor, but it's arguably the most important factor," said George Washington University associate professor John Sides, who has created a computer model to analyze the impact of the economy on the presidential campaign.
"The forecasting model suggests a very close race with maybe a slight edge to Obama, but not necessarily a large edge -- nothing he can be very confident in," Sides said.
Obama faces a perfect storm that threatens to sink his prospects of a second term.
The price of gas is dropping but is still high. The stock market remains volatile, unemployment ticked up again, and the eurozone crisis lingers.
In a brief statement Friday after which he also took a few questions, Obama described the depth of the nation's troubled economic recovery.
"The hole we have to fill is much deeper, and the global aftershocks are much greater," he said.
Sides has crunched the numbers, using the president's approval ratings, economic conditions and consumer confidence. He compares those factors to past presidential races.
What his models show him is that the president is facing similar conditions to what former President Jimmy Carter faced when he lost to Ronald Reagan in 1980, with one exception: Carter was less popular than Obama among his own party.
"The president can count on a reservoir of support in his own party that previous Democratic presidents may not have been able to count on," Sides said.
The gloomy news adds to the national frustration and could weigh on some voters.
"The best thing the president can hope for is not just a good economy but good economic headlines," Sides said.
According to a CNN/ORC International poll, most Americans have doubts about which of the two presidential candidates can fix the problem.
But a slight majority, 50% to 44%, says Romney has the right kind of business experience for the task, despite attacks by the Obama campaign on the former Massachusetts governor's record at private equity firm Bain Capital.
The poll's margin of error is plus or minus 3.5 percentage points.
Romney uses the slow recovery to cast the president as a failure who is in over his head and frequently defaults to the blame game.
"The president's message in all this -- have you heard his campaign slogan? Forward! Forward! Forward over a cliff," Romney joked with supporters at a campaign event in Council Bluffs, Iowa. "He is looking around; he is trying to find someone to blame."
To help lift the economy and his campaign too, Obama is putting pressure on Congress to pass items on his "to-do" list, even though Republicans aren't likely to act anytime soon.