- “"Eric, you are the only one who has a chance to beat Senator Davis Graham in the primary!"”
- ―Eric repeating Wolff's words
Eric Matthews is recruited to run for the Senate, but learns it was only because they expected him to lose. Riley and her friends rally together to help his campaign.
- Rowan Blanchard as Riley Matthews
- Ben Savage as Cory Matthews
- Peyton Meyer as Lucas Friar
- Sabrina Carpenter as Maya Hart
- Corey Fogelmanis as Farkle Minkus
- Danielle Fishel as Topanga Matthews
- Will Friedle as Eric Matthews
- Danny McNulty as Harley Keiner
- Nicholas Hormann as Senator Jefferson Davis Graham
- Lamont Thompson as Zachary T. Wolff
- J.B Gaynor as T.J. (Tommy) Murphy
- Tess Paras as TV Newscaster
- The title is a play on the 1939 classic movie Mr. Smith Goes to Washington starring James Stewart.