It's partly a matter of economics, which have gone well under Erdogan. It's also simple demographics. The western "secular" populace is in relative decline while the more conservative, central and eastern, populace is in ascendance. That's Erdogan's constituency. They *want* a more Islamic Turkey. This is the same cohort that, when I traveled from Turkey overland to Iran decades ago, gave me a hard time because they saw Israeli writing on the food I was carrying.
U.S. Democratic Senator Merkley airs support for Iran nuclear deal (Reuters)
from the article: Netanyahu had the courage to stand up to Obama