Managing with Power (1992) is a classic text by Jeffrey Pfeffer at Stanford University. This is another one I wish I had read when it was first published. Pfeffer gives the reader a way to diagnose the sources of power in organizations and government. Great ideas don't move themselves through organizations, but require power and influence to see them implemented. He provides numerous case studies of companies where powerful decision makers either helped or hurt their organizations.
Great read, highly recommended. I'll read it again when I have a chance.