I am an optimist but still having lived in many countries and various cities, one common factor I have found is: corruption at every political level in almost every community.
It doesn't matter if a country is a democracy or a dictatorship, no system has proved successful in weeding out corruption completely. It seems that in many places, politics is seen as a lucrative career choice because of the possibility of kickbacks and bribes. For most budding politicians, these are the perks of the trade and par for the course. In most countries, politics is the only sure shot way to becoming wealthy over night.
I am afraid, at least in our lifetime, politics may never be corruption free.