French Jews might be French, so what? They might not, so what?
A second (or third, or fourth) generation French citizen from Algeria might not be "French". Why? Would the decendant of a Polish immigrant from 1840 be "French". If you like LePen, then, what is an "American"? Do you really think government should be establishing laws and preferences based on race and/or religion? It was tried in Europe last century at the cost of tens of millions of lives. I fear we're facing the same problem as we enter this millenium, but at least we should recognize it as an evil.
I see nothing wrong with opposition to immigration that would make the French a minority in their own homeland. As for the Poles (and the Portuguese who also immigrated there, and the Jews as well) they assimilated and became French. The Arabs aren't doing so. And America is a poor example of comparision to France; France is not a "nation of immigration" so those cliches don't apply to France.