You can't fight City Hall.
Edison has been mayor since almost the first days of the city in the dark. While Tesla was putting up the wall that held the fog at bay, Edison and Lenora Piper were working on a way to deal with the unquiet dead of the city. The creation of the Hereafter was as important to the survival of the city as Tesla’s Wall and Edison, ever more politically adroit, rode the acclaim of the citizens into the mayor’s office.
Under Edison’s blunt guidance and talent for organization, the new structure of the city government emerged and started to thrive. While not all of Edison’s attempts at defending the city have worked out (his automated policemen, for example, are considered a mixed blessing at best), Edison has a talent for keeping things running smoothly. Even himself, long after death.
Upon hearing that Tesla was made immortal, Edison set out to grant himself the same boon. Using the same principles as the Hereafter, but turning the entire government building at 1 Centre into his ‘afterlife’, Edison survived the death of his body to become the living avatar of city government.
This might prove problematic if he loses an election for mayor, but that hasn’t happened yet and with City Hall running the elections, it doesn’t look likely anytime soon.