What is the importance of Washington D.C. in the novel, Hope Never Dies: An Obama Biden Mystery?

Washington D.C. is the capital of America, and the home of much of the nation's political activity. These two circumstances are the core context for the development of the professional and personal relationship of Barack Obama and Joe Biden, both in the real world and in the novel. A few of its key scenes take place there, and it is Joe's destination at the novel's conclusion, having solved both the crime he had been investigating and his doubts about the state of his friendship with Barack.