In the last 20 years France internal security main concern has been to quell any criticism and warning about the islamic threat.
Concerned citizen expressing their legitimate worries about the taking over of whole cities by islamic rule were persecuted and prosecuted with the result that islamists felt legitimated and citizen felt abandoned by the state.
This lead to many voting for the only ones that denounced that sorry state of affair, the far right.
No government wanted to confront the disruptive message of islam, sharia law, jihad doctrine and oil paid incitement.
It's too late, some say that 15-20% of the population is muslim and who knows how many "useful idiots" ready to unleash their self hate towards the West civilization.
It all started in 1973 with the "eurabia" agreements, just google it.