We need to gain Power to get work done. This is Power helps a manager to sail through the problems and can manipulate/influence a team/stakeholders and organization to move in certain direction he wants. It comes through various way we already know through our books like, Position or Expertise.
Recently read about Atari and Apple, how both companies went outside computer industry and hired CEOs to sail them form a start-up culture to more organized way. And we know that Apple’s new CEO completely lost it, reason being expertise. He never invested in expertise of understanding Computer Industry at that time and lost it.
So as PM if you need a real power get into trenches and do not hesitate to understand the Arch Diagrams or at least the basic requirements of Project.