Le Pen Joins Volatile Race For French Presidency

Bayrou has portrayed himself as an alternative for voters unhappy with the personalities or politics of Sarkozy and Royal. He has said he favors business reforms and reduction of the French debt, yet would maintain the country's strong social services network. He has said he would include people from all major parties in his cabinet.

But voters have been drawn to him less for his policy positions, which often are amorphous, than for his image as an honest, straightforward politician. His rankings have shot up by at least 10 percent in most polls in the past month, though his support base remains softer than those of the two leading candidates.

Of all the candidates, Le Pen has the most fiercely loyal followers, many of whom will not admit their support to pollsters. That is one reason why Le Pen's opponents view his candidacy with such concern; he usually wins a higher percentage of votes than surveys initially indicate.

Although he was a lone wolf in the 2002 campaign, denouncing immigration and espousing protectionist social and trade policies, many of his views became part of mainstream political debate after violence and arson swept the country's suburban slums, populated largely by immigrants and their French-born offspring, in the fall of 2005.

But many French are appalled by what they consider to be Le Pen's racist and anti-Semitic views. He has been convicted of calling the Nazi gas chambers "a detail" of World War II -- Holocaust denial is a crime in France -- and for inciting racial hatred by saying France was in danger of being overrun by Muslims.

He has tried to improve his image with campaign posters that show him walking with a group that includes a black woman, under the slogan, "Together, Let's Lift France Back Up."

Researcher Corinne Gavard contributed to this report.