In January 2006, Smart joined the cast of the Fox series "24", playing the mentally unstable First Lady of the United States, Martha Logan, to actor Gregory Itzin's President Charles Logan. She received back-to-back Emmy nominations for Outstanding Supporting Actress in a Drama Series and Outstanding Guest Actress in a Drama for the role in 2006 and 2007. She also appeared in several films between 2006 and 2010, including the Curtis Hanson drama, "Lucky You" (2007), opposite Drew Barrymore; "Youth in Revolt" (2009); and the independent comedy "Barry Munday" (2010).