His latest book, “France Has Not Said Its Last Word Yet,” which he released in September to mark his unofficial entry into the presidential race, has sold more than 250,000 copies.
But some of his books have contained incendiary statements about women and minorities, as well as historical inaccuracies in the course of efforts to clear France of wrongdoing in some of the worst episodes of its past, including in World War II and Algeria’s war for independence from France.
Mr. Zemmour’s 2014 best seller, “French Suicide,” sought to rebut the historical consensus that Vichy, France’s collaborationist government, was responsible for the notorious roundup of Jews during World War II.
Mr. Zemmour is the son of parents from Algeria, and he styles himself as a defender of France’s Christian civilization against the influence of Muslim immigrants. But he himself is Jewish, and his repeated attempts to rehabilitate the Vichy government, and its leader, Marshal Philippe Pétain, have split France’s Jewish community.
Mr. Zemmour has also excelled as a right-wing television pundit deploying virulent nationalist, anti-immigrant rhetoric. In 2019, he joined CNews, a Fox-style news network, which provided a platform for him to express his ideas to hundreds of thousands of viewers during prime time.
Mr. Zemmour has experienced a rapid rise in the polls over the past few months, fueled by feverish media coverage of a tour for his latest book, but he has stumbled in recent days.
Several supporters, including a key French financier who had lent money to Mr. Zemmour, have distanced themselves, describing his campaign as amateurish. Recent campaign stops have also cast doubt on his ability to handle the challenges and pressures of the campaign trail.