Book excerpt: How does an idea's time come? -- Participants on the inside of government -- Outside of government, but not just looking in -- Processes: origins, rationality, incrementalism, and garbage cans -- Problems -- The policy primeval soup -- The political stream -- The policy window, and joining the streams -- Wrapping things up -- Some further reflections -- Epilogue: Health care reform in the Clinton and Obama Administrations -- Appendix on methods.