Lessig makes the case that Congress is corrupt – not in the “directly taking money for votes” way, but just the fact that Congresspeople are desperate for money so they can get reelected, so lobbyists who can provide more campaign fundraising get more access. This is not a hard case to make.
He also talks about possible solutions, but it was depressing how out of reach these seem. The most likely one is a Constitutional convention, so…yeah. Good book, but fairly depressing.