Through the eyes of Jack Burden, we follow the rise and fall of Willie Stark, a politician in a Southern State in the USA. Originally an idealist (his biggest project is to build a hospital that offers care for everyone, for free), he soon learns that achieving his goals is practically impossible without corruption.
Jack observes this development of his friend and boss. More than a story of Willie Stark's career, this novel follows Jack's personal development. He falls in love with his childhood friend Anne, starts studying Law - a topic that doesn't interest him in the least, but he chooses because he suspects his girlfriend expects him to study it -, but breaks up with her for a reason unbeknownst to himself. He becomes a journalist and somehow ends up being Willie Stark's right hand, helping him in corrupt businesses which also makes him manipulate his childhood friend Adam, Anne's brother, and attempt to manipulate Judge Irwin, a longtime friend of his mother and a kind of mentor for himself - with fatal effects.
Over the course of time, Jack has developed a nihilistic approach, seeing himself as merely an observer of life and his relations, but a number of events make him realize that everything that happens does have a direct cause, and in turn every action he takes has consequences.
A very strongly written book, deeply psychological, and the language and style is much fun to read.