In theory, one of the main achievements of French republicanism is equality.

But, as the publication of a new poll has shown, not everyone in France thinks it is a good idea to test how equal and tolerant France really is. Shock dominated the reactions when respected weekly Le Journal Du Dimanche published the results of an extensive survey on racism last week. The poll asked such questions as whether racist reactions "can be justified" or if respondents would "react badly if their daughter married a Muslim," according to a translation by the TV station France 24.

But it wasn't the results that outraged some commentators. It was the fact that the poll existed at all. The conservative newspaper Le Figaro, for instance, said the polling institute behind the survey had acted illegally by conducting it. On Twitter, users said the institute should be sued.

There's a surprisingly easy — but in many ways also confusing — reason for that reaction: Collecting information about ethnicity or religious beliefs is generally prohibited in France. And that's exactly what Ipsos, the polling institute responsible for the survey, claims to have done. Amid recent physical assaults against Jews living in France, the people behind the survey say they wanted to provide precise numbers that expose the true extent of the problem. Hundreds of people were pre-selected, based on their religious beliefs, and some answers were broken down in a way that showed what Jews and Muslims thought of each other.

Although the collection of data related to ethnicity and religious beliefs can be authorized by the country's data protection agency in exceptional cases, France's constitutional court has not hesitated to prohibit certain questions from being asked or published in the past. The law — which was passed in 1978 — also has historical origins: Particularly in the decades after Jews were ordered to sew yellow stars on their clothes during WWII, questions about citizens' ethnic or religious identities had a bitter connotation.

In France, every French citizen is supposedly equal by law — an ideal that was established during the French Revolution. Values such as equality and secularism have historically carried greater significance in France than multiculturalism.

Many migrants in France, however, believe that their government's "all citizens are equal" approach has actually achieved the opposite. The lack of data on citizens' religion, race or ethnicity has made it hard to analyze the extent of discrimination in France and to implement programs to help disadvantaged citizens find jobs or secure spots at top universities.

The survey's authors did not reply to a request for an interview about the poll, which used opt-in online panels rather than randomized polling methods. But the results are among many indications of a growing racism problem in France: Previous surveys, for instance in 2006 and 2013, reached similar conclusions.

The French Judaism Foundation, which commissioned the poll, reportedly defended it as being "serious" but acknowledged that it had debated whether to publish the results. Several years ago — when criticism of the French idea of equality was far less common than it is today — the poll probably would not have been published.

Anxiety among French Jews has increased since 2012 — the year several people were killed in a terror attack on a Jewish school in Toulouse, a city in southern France. The Jewish Agency, which manages Jewish migration to Israel, recently reported that 8,000 French Jews left the country for Israel in 2015.

For Muslims, who are believed to constitute about 7 percent of the French population, the last years have also been challenging. French suburbs have frequently been singled out for making it hard for younger Muslims to find jobs or be accepted at prestigious universities. Conservative and right-wing politicians have been accused of deepening that divide. When a series of riots in French suburbs erupted in 2005, then-Interior Minister Nicolas Sarkozy called the perpetrators "racaille" — which translates as "scum." More liberal commentators, however, have argued that the frustration of young French Muslims is deeply rooted in the country's failure to integrate them.

Research suggests that the current poll's findings may indeed point at a widespread problem. Discrimination "is challenging the French model of integration and the Republic's promises of equality," demographics researcher Patrick Simon concluded in a paper published in 2012. "Beyond the loss of opportunities in the labor market and social life, experiences of discrimination are associated with a higher feeling of rejection from Frenchness and a sense of isolation."

In an email exchange with Simon at the end of 2015, he noted that "there are other consistent findings that prove that there is a specific discrimination against Muslims in France." Job applicants with foreign-sounding names are much less likely to succeed in pre-selection processes, for instance.

A survey by the Migration Policy Institute found that 45 percent of immigrants in France believe they aren't considered to be as French by other citizens. Among the children of immigrants, 36 percent say the same. The Charlie Hebdo shootings last January, and the attacks in November, have probably widened that societal divide.

"Hostility and hate speech against Muslims were already on the rise before the attacks and one can expect — or fear — that they will be seen even more acceptable and legitimate after these horrific events," Simon said, referring to the most recent attacks.

"Let’s face it: The integration in France does not work as well as we would like to believe," said Julien Théron, a political analyst at the University of Toulouse.

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