While its possible there were policy mods in the past, I have yet to find them, or any that work. That said, I would like to request that Paradox be willing to offer either a very very simple dlc, that allows us to edit elements in cities skylines that we couldn't before, such as policies, demand sliders, and various other elements. Maybe even with a new editor to assist in the development of future mods. Its an idea, good or not. Thought I would put it out there, just in case a dev was looking for ideas.