Valls is deliberate and—unusual for a French politician of the left—blunt in identifying the main culprits in the proliferation of anti-Jewish violence and harassment: Islamist ideologues whose anti-Semitic and anti-Western calumnies have penetrated the banlieues.

Again, he's the Prime Minister -- and on the left to boot -- so, one would imagine him to be credible on this issue.

But while this demographic is the most visible, there are other ingredients in the stew -- the paragraph cited above continues with Valls' thoughts on this:

But he goes further: France’s “new anti-Semitism” is also the product of what he understands to be a malicious sleight of hand on the part of Israel’s enemies to repackage anti-Semitism as anti-Zionism.

“It is legitimate to criticize the policies of Israel,” Valls said. “This criticism exists in Israel itself. But this is not what we are talking about in France. This is radical criticism of the very existence of Israel, which is anti-Semitic. There is an incontestable link between anti-Zionism and anti-Semitism. Behind anti-Zionism is anti-Semitism.”

Frequently, Valls said, anti-Zionists let the mask slip. It is impossible, he said, to ascribe the attacks on synagogues—at least eight were targeted in France last summer—to anger over Israel’s Gaza policy.

[0] http://www.theatlantic.com/magazine/archive/2015/04/is-it-ti...

I frequently see misanthropy or xenophobia masquerading behind specific racist/sexist/theist/etc slurs.

It's a bit like the trouble Americans seem to be having with racism, in that a whole generation of kids was taught that racism looks like the KKK or Jim Crow Laws. Far more prevalent and insidious though, has always been the deeply held belief that people know you only talk about among 'like minded' individuals. That way of thinking is much older than the KKK; it gave rise to the KKK. You can kick down an organization, but you can't do the same to a mode of thinking.

You can only outlive it.