You could plant a puppet as the city's leader.
- You pick a likely candidate to win the election/primogeniture who is not terribly clever.
- You approach this individual, befriend them, and slowly subvert them into your puppet.
- You help him become the city's leader and control the city through him.
Funnily enough, there is a possibility that something similar is already happening in Korea, without any super powers. You can read an article about it here:
At the moment, one of the close associate with President Park, Choi, was found to be involved in a pretty severe financial scam with the government.
Funny thing is Choi's plot goes all the way back to her father and then-president Jung-Hee Park who happens to be current President Park's father.
The summary of what probably happened is this:
- Choi's father, a charismatic cult leader approached young Gun-Hee Park whilst she was grieving for her mother's assassination.
- As Park rose to power, Choi's family backed her both financially and psychologically. Choi befriended Park and became a life long companion.
- As Park became the president of South Korea, Choi became more actively involved in Park's life. Going so far as Park sending Choi his speech drafts for "editing."
- Choi becomes involved/masterminds a racket to pressure corporations to give "donations" and siphon the money to overseas.