Bradley Whitford states in an interview on the Season 1 DVD that he was originally cast as Sam , though the character of Josh was the role Whitford had wanted and for which he had auditioned . In addition , Josh 's character had been written specifically for him by Aaron Sorkin . In an interview on the Season 1 DVD , Bradley Whitford said he was originally cast as Sam , even though Aaron Sorkin had created the Josh character specifically for him .