By 1973, the total North African population of France in all probability had exceeded one million. When Valery Giscard d'Estaing became president of the republic in May 1974, right after the Yom Kippur War and the oil shock, he was quite concerned about this number. He earnestly tried to reverse the trend, first by formally putting an end to the economic immigration policy, then by initiating a policy to repatriate (or "reemigrate") the migrant workers from North Africa. He failed miserably in both efforts, however, for the utter ideological incorrectness of these policies, in terms of both domestic politics and foreign policy, required so many qualifications that the entire scheme was rendered unworkable. For instance, the measures of July 3, 1974, were articulated in such as way as to infringe neither on human rights nor family rights: however unwelcome they were, migrants actually received new subsidies for housing, welfare, and education. They also won permission to bring in their relatives -- even polygamous wives.
The efforts of Giscard d'Estaing brought about another dramatic increase in Muslim population, so that by 1981, when François Mitterrand became president, some 2 million North African Muslims lived in France. For the most part, they were either French citizens themselves or the parents of French citizens. In retrospect, French Islam reached a critical mass at this time, becoming a permanent element of French national life.
Well he did try didn't he?