When confronted with a real visceral issue like Islam in Western countries, I am like a Republican bristling at paying higher taxes so someone can go on the dole. I emotionally want to protect territory. To me, it appears that fundamentalist religious belief is a threat to secular-humanist values like the separation between church and state. Therefore I am against fundamentalist religious belief.
Individual cities, however, have much higher concentrations. Karoly Lorant, a Hungarian economist who wrote a paper on the subject for the European Parliament, calculates that Muslims already make up 25 percent of the population in Marseilles and Rotterdam, 20 percent in Malmö, 15 percent in Brussels and Birmingham, and 10 percent in London, Paris, and Copenhagen. If the French national figure of around 5 million were proportionately reproduced in the US, it would make for 24 million American Muslims. Moreover, given that immigrant Muslims have a higher birthrate than indigenous white Europeans or other immigrant groups such as Eastern Europeans or African-Caribbeans, that population seems set to increase, regardless of tighter controls on immigration now being imposed by governments.