I know someone who works in the US State Department, so I asked her, half-jokingly, whether she had any insider information on what's going on in Turkey. Here's what she said (edited for privacy—sorry for all the redactions):
If only I knew what the hell was going on! I served my tour in Adana, Turkey as [redacted] from 20XX-20XX. Erdogan's AKP party was just getting rooted and the opposition pushed out—but democratically, the people have elected AKP for the past 15 years and the military has been summarily squeezed out. This absolutely bizarre turn of events has astonished me. Not sure about the timing, above all. Why now? Why not five years ago when all the upper ranks and echelons were being witch-hunted for ties to an alleged "deep-state conspiracy" called Ergenekon?
So there we have it. The best I could do on short notice.