Brought in by Secretary McCord as a consultant after she takes over the State Department, Barnow becomes one of her closest political allies, developing a reputation in D.C. as the Secretary's 'hatchet man'. When she announces her intention to run for the presidency at the end of Conrad Dalton's term, he becomes her campaign manager.
After Elizabeth is elected as President in the 2020 presidential election, Barnow serves her as White House Chief of Staff for her first 100 days in office. After the successful passage of her signature ESI bill and the end of the 100th day, Barrow resigns as Chief of Staff and is replaced by Russell Jackson. Nevertheless, he remains as a Counselor to the President and one of the most senior members of the McCord administration.
He is a Rhodes Scholar with a "brilliant legal career" and a "promising political career" which was "derailed by a scandalous divorce 6 years [earlier]" according to Daisy Grant. He is currently working as "couch sitter" or someone who "moves through a cabinet member's office and dispenses cool, calculated advice" (a.k.a. firing people).
He is really attached to his Dog, Gordon. According to Mike B, Gordon was the only thing in his life which was completely truthful to him, like without any filter, and when Gordon died, Mike was really devastated.
He is also known as "The Hatchet Man". Elizabeth decided to bring him in as a consultant to reorganize the US State Department after her "entire staff let [her] hang [herself] in front of a nationally-televised congressional hearing". Elizabeth and Barnow both taught at the University of Virginia.
- He has a dog named Gordon
- He dated Nadine Tolliver in season 3
- He has a fat son who later turned out to be a good student, who got into Yale, mostly because of lacrosse. He is a fluent spanish speaker.