PARIS — There have been many startling elements to Éric Zemmour’s as yet undeclared campaign to forge a hard-right path to the French presidency, but perhaps none as surprising as his attempt to rehabilitate France’s collaborationist wartime regime.

“Vichy protected French Jews and gave the foreign Jews,” Mr. Zemmour said in September on CNews, a growing Fox News-like TV channel, one of several remarks suggesting that the wartime government of Marshal Philippe Pétain that sent more than 72,500 Jews to their deaths was not so bad after all.

The comment was shocking not least because Mr. Zemmour is Jewish. From 1942 onward, there is no evidence that the Vichy regime tried to protect French Jews. It collaborated with the Nazis to round up Jews, whether foreign or French.

Clearly borrowed from the Trump playbook of staying at the top of the news through provocation and outrage, Mr. Zemmour’s declarations have divided the French Jewish community and made the unsayable sayable. But they have not slowed the giddy rise of this smooth-talking TV star and author, with the French presidential election less than six months away.

Mr. Zemmour, 63, is a noncandidate who has done nothing to deny intense speculation that he will soon become one. A poll published last week by the daily newspaper Le Monde gave him as much as 16.5 percent of the vote in the presidential election next year, enough to qualify for the second-round runoff between the two leading contenders.

“He is dangerous, and he insults Jewish morality,” Bernard-Henri Lévy, a leading Jewish author and intellectual and one of Mr. Zemmour’s most prominent critics, said in an interview.

French news coverage of Mr. Zemmour — and it is relentless — has tended to ignore his Jewishness in keeping with the universalist national tradition that favors burying ethnic or religious affiliation in undifferentiated Frenchness.

This reticence, however, has begun to fade as the Jewish community has splintered in intense debate over Mr. Zemmour’s ascendancy, and the country wonders how to deal with xenophobic and revisionist vitriol spilling from the lips of a Jew of Algerian descent. Mr. Zemmour’s family came to France from Algeria in 1952.

“We’ve spent 20 years trying to explain to politicians who did not want to see it that there is an Islamist antisemitic threat in France,” said Simone Rodan-Benzaquen, the French managing director of the American Jewish Committee in Europe. “That becomes more complicated when it looks like Jews are racist, when racism in all its forms gets legitimized and when a cohesive Jewish position gets profoundly split by Mr. Zemmour.”

The French Jewish community of about half a million people is the largest in Western Europe. Some of them, particularly those of Sephardic descent living in poor suburban areas where episodes involving antisemitism from the Muslim community have become more common, find Mr. Zemmour’s uncompromising anti-immigrant and anti-Islam message appealing.

“There is a part of the Jewish community that sees in him the man who will resolve problems of security and violent Islamism,” said Francis Kalifat, the president-elect of the Council of Jewish Institutions in France. “But you have to see his whole message, which, while full of love for the grandeur of France, drags the country back to what was most detestable in its history.”

Mr. Zemmour, speaking on France 2 TV in September, implied that neither the killer nor the three children who were victims of a 2012 terrorist attack on a Jewish school in Toulouse were really French because they were all buried outside France — Mohammed Merah in Algeria and the Jewish children in Israel. A rabbi was also killed.

“Anthropologists teach us that we come from the country where we are buried,” Mr. Zemmour said. “They did not belong to France.” He added, “The French drama is we don’t make French people any longer.”

The remark prompted some outrage in the Jewish community. Still, Elizabeth Lévy, in the far-right magazine Causeur, argued later that month that Mr. Zemmour represented “the last chance before exile” for many North African Jews in France who regularly encounter antisemitism. In this light, it was worth “closing one’s eyes to a few excesses.”

In a France where the pandemic, terrorism, immigration and sharply rising energy prices have caused widespread anxiety, Mr. Zemmour has contrived to attract a slice of the far-right vote of Marine Le Pen, the perennial candidate, but also some of the conservative center-right drawn to his glib intellectualism.

“Some of the guilt disappears for moderate conservatives because they know they can’t be accused of being racist if they vote for a Jew from North Africa,” Ms. Rodan-Benzaquen said.

Mr. Zemmour, who has spoken little of his Jewishness, did not respond to requests for an interview. In 2014, he told the center-right French weekly Le Point that he keeps kosher at home and does not believe in God, but that he sometimes goes to synagogue on high holidays. He told Sud Radio this month that “I am greeted very warmly when I go to synagogue.”

The reluctance to address the particular issue of a Jew’s racism in a country where Jews were deported en masse to their deaths eight decades ago largely fell away this month. An article by Mr. Lévy in Le Point titled “What Zemmour Does in the Jewish Name” ignited intense debate, in part because the subject had not previously been addressed so frontally.

“Seeing this man not only profane his name, but also become the sword-bearer of everything Jewish hope has fought against for millenniums, is of an unbearable obscenity,” Mr. Lévy wrote. Mr. Zemmour’s “nationalist and racist hubris” was an insult to all that Jewish morality, humanity and the idea of the “luminous figure of the stranger” had contributed to France.

Mr. Zemmour pulled no punches in a riposte on CNews. He called Mr. Lévy “a traitor.” In an allusion to another politically engaged French writer, André Malraux, he said Mr. Lévy was “a carnival Malraux who must absolutely fight his Spanish Civil War every two years.”

The reference was to Mr. Lévy’s passionate stand over decades for oppressed people from countries like Afghanistan, Bosnia and Nigeria, illustrated in his powerful recent book and movie, both called “The Will to See.” Mr. Zemmour quoted a phrase of Rousseau: “Beware of those cosmopolitans who search in their books for duties they disdain at home. Such philosophers love the Tartars in order to be spared having to love their neighbors.”

Mr. Zemmour’s own love of his neighbors is selective. Of France’s estimated six million Muslims, close to 10 percent of the population, he has said they should “be given the choice between Islam and France,” suggested their deportation might not be impossible, claimed they all consider jihadist terrorists to be “good Muslims” and said he would ban all “non-French names,” like Muhammad.

In 2019, in remarks that led to a conviction and a fine from a Paris court for “insult and provocation to hatred,” Mr. Zemmour said that “an Islamization of the street, like the uniforms of an occupying army, reminds the defeated of their submission.” In the 1930s, he added, the most lucid observers “compared Nazism to Islam.” He did not identify those observers.

“He spreads hatred and it seems somehow natural and that is appalling,” said Hakim El Karoui, a Muslim business consultant. “What he says of Muslims would never be accepted if said of any other group.”

Mr. Zemmour has never denied the Holocaust, which is illegal in France. But his remarks about Vichy are part of a habit of playing light with history.

After decades of equivocation, Jacques Chirac, then the president, acknowledged in 1995 the full extent of Vichy’s collaboration with the Nazis. It included use of the Vel d’Hiv, an indoor cycling stadium in Paris, to detain some 13,000 Jews, including 4,000 children, who were rounded up and deported to Nazi death camps. Some 80 percent of the children were French.

Mr. Zemmour, whose 2014 book “The French Suicide” was a best seller, has also reopened the Dreyfus Affair, saying last year that the innocence of Alfred Dreyfus, the French Jewish army officer falsely accused of treason, “was not evident.”

Both Ms. Rodan-Benzaquen and Mr. Kalifat said they do not believe Mr. Zemmour is an antisemite, however odious they find his view of French identity and history. “He is more of a revisionist,” Mr. Kalifat said.

Jean-Marie Le Pen, the 93-year-old rightist who led the National Front, now the National Rally, for almost 40 years and who is the father of Marine Le Pen, has said he will back Mr. Zemmour because of his “courage and culture” and his defense of Vichy.

“The only difference between me and Mr. Zemmour is that he’s a Jew, so it’s difficult to qualify him as a Nazi or a Fascist,” Mr. Le Pen told Le Monde this month. “That gives him great freedom.”