According to the DVD commentary, Sorkin intended to center the show on Sam Seaborn and the other senior staff with the president in an unseen or a secondary role. However, Bartlet's screen time gradually increased, and his role expanded as the series progressed. Positive critical and public reaction to Sheen's performance raised his character's profile, decreasing Lowe's perceived significance. In addition, according to Sorkin, the storylines began to focus less on Sam and more on Josh Lyman, the deputy chief of staff. This shift is one of the reasons for Lowe's eventual departure from the show in the fourth season.