I agree, they shouldn't be there, especially in those numbers. I was in France a couple of months ago and I felt weird surrounded by 40% blacks and 40% north African Arabs. I don't know why so many exist, maybe cause of the previous French occupation?
You're quite the drunk poster lately 
Because of socialism first, and political cowardry second.
Everything started in 1981 with the election of Francois Mitterrand, a socialist,
1-he vote the "law of the ground" and the "law of the blood".
= If you born in France you're automatically french, if one member of your family is french, you become french.
2-after he voted the "family gathering" = ex arab or african make all his family coming from africa or maghreb.
3-illegal immigration = each year 100000 illegal alien are regularised.
4-every time a political try to do something against, socialist argue that France is "the land of freedom and human right",
5-in the same time media play a huge role by speaking about racism, colonnialism, slavery, etc etc...it's called "ethnomasochist", they gave us no reason to be proud of being French, and living in perpetual repentance.
6-the success of an immigration depend of the quality of immigrant, in the case of the France all the lazy ass, scum bag of maghreb and africa come in France, so the immigration is a total fail.
7-natality = in France, the less you work, the more you got, so while average citizen are working, the other are making children.