Over the course of his term in office, Sarkozy has had the lowest opinion poll rating of any French president in more than half a century. If he makes it to the runoff voting on May 7, Hollande would trounce him by 56 to 44 per cent, according to the latest surveys.
Several factors explain why the man who rode so comfortably to victory in 2007 is now on the rack.
One is bad luck. In 2008, the financial crisis began to brew, developing into a storm that battered Western economies and threatened the single European currency. For any incumbent in any country, this would be tough going.
But another is the hefty question mark placed against Sarkozy himself.
French voters who prefer a calm, avuncular figure as head of state were swiftly disappointed by Sarkozy's mercurial manner, flashy Rolex-and-Rayban dress sense and fondness for partying with tycoons and celebrities.
His three marriages, the latest to former supermodel Carla Bruni, left starchy conservatives and Catholics deeply unimpressed.
For business people, the biggest doubt has been Sarkozy's handling of the economy, where he has flipflopped from being pro-market to favouring state intervention.
To stop the economy from sliding into recession, Sarkozy drove up borrowing to the point where the world's fifth largest economy has been stripped of its coveted "triple A" credit rating in the bond market.
Even so, Sarkozy is never more redoubtable than when things are against him. A conservative activist since the age of 19 and a town mayor at just 28, he is France's toughest political street fighter - smart, dynamic and ruthless.
Already, in the weeks before he officially announced his candidacy, Sarkozy has been stealthily planning to recover lost political territory.
He has been burnishing his record as a statesman, his strongest suit, in tackling the euro crisis.
He has also set out a conservative agenda on social issues, with a promise to restrict immigration. He also unveiled proposals to ease payroll charges for employees, and in a gesture to the left, to impose a tax of 0.1 per cent on financial transactions.
Add this agenda to Sarkozy's whirlwind style, and the campaign is likely to be jarring.
"The game is far from over. The opinion polls, the commentaries, all this will be a clean slate three weeks before the election," his prime minister, Francois Fillon, told Le Monde this week.