a genuinely democratic party ever came to power in Bulgaria, you'd need a clean sweep of the edu, judiciary, military and police force as well.

Really? And who would you replace all the teachers, lawyers, judges, military men and police people with? Would you rather have someone completely incompetent or someone who you don't fully trust? If anything, you can have a democratic party that comes to power, but the state will no longer work and there will be very bad consequences just due to the fact that you have changed so many things. Nothing will function anymore, for a long time. That is not to say that there is such a thing as a democratic party. A party has it's own views on how to run things, even if elected, it will do so according to their views. The fact that they'll put people in power that are "democrats" is really not that different than what Erdogan is doing. The only difference is that you're starting with a presumption of innocence that they won't abuse their power. Given that pressure on public institutions comes from a long development of a state, and pressure from the public society at large, odds are that the so called democrats will become corrupt as well.

All-in-all, you don't change a society overnight. Bulgaria is what it is, and any change needs to be done step-by-step over a long ass process. Accept it as it is, and work towards making it better.