Someone else already said the World of Darkness games like Vampire. I'm one of the dozens of people who prefered Requiem over Masquerade, but either should work for you.
I'll also throw out my current game crush: Fate. It's a general purpose system, so it focuses where you point it. Players are encouraged to come up with the major "Faces and Places" in the setting, along with the big issues, and then pursue their goals in that world. That could be as much about getting a favored candidate elected as taking out a corrupt CEO.