Rush is the Founder and Artistic Director of Stanford Repertory Theater (SRT). He has directed many productions for the company, including Voices of the Earth: From Sophocles to Rachel Carson and Beyond; Polar Bears, Black Boys & Prairie-Fringed Orchids; Hecuba/Helen (co-adapted with Courtney Walsh); Democratically Speaking; Four-Sided Triangle; Clytemnestra: Tangled Justice; Words and Images to End All Wars; Moby Dick – Rehearsed (with Courtney Walsh); Copenhagen; Under Milk Wood; The Exception and the Rule; Lysistrata (adapted by Amy Freed); An Inspector Calls; Betrayed; Electra; Libation Bearers; Curse of the Starving Class; The Wanderings of Odysseus; Happy Days/ Oh les beaux jours; Life of Galileo; Faith Healer; Omeros; War of the Worlds; Deianeira; The Collection (with Ed Iskandar); and The Bear (with Aleksandra Wolska).

He has appeared in Hay Fever (Richard Greatham), Waiting for Godot (Pozzo), The Chairs (Lecturer), Biedermann and the Firebugs (Biedermann), The Lover (Richard/Max), Old Times (Deeley), Les Blancs (Charles Morris), Uncle Vanya (Astrov), and Reykjavik (Ronald Reagan). Rush has worked as an actor or director at various regional theaters, including Magic Theater, TheaterWorks, Cutting Ball, Arena Stage, Guthrie Theater, Alliance Theater, Seven Stages, McCarter Theater, the Pram Factory, and La Mama (Melbourne).