What is a "Islamic party"? Turkey is something like 96% Muslim population, so chances are, any particular cross section of society might just be called "Islamic" something, including the government.
That 96% is the amount of people registered as Muslims, and the religion status are registered at birth as parents declare. Further, who's not a registered Christian or Jewish is considered a Muslim by default. So that 96% includes: atheists, converts to religions other than those of book (Islam, Christianity, Judaism), Alawites (10 million of them, and Turkey's population is 70million), secularists and the non practising Muslims (edit: i.e. who are only nominally Muslim because parents are).
