Sophia Bush was originally set to star in Terminator 3: Rise of the Machines, so why was the actress replaced by Claire Danes during filming? The franchise began with James Cameron’s slasher-influenced action film The Terminator in 1984. It starred Linda Hamilton and Michael Biehn as the heroes on the run from Arnold Schwarzenegger’s titular android assassin, the original Terminator was an ambitious sci-fi horror that spawned numerous sequels of varying quality.
Although she returned for the critically-derided 2019 sequel Dark Fate, Hamilton left the series after its blockbuster second installment Terminator 2: Judgment Day. The movies soon struggled to find a lead actor as engaging as Hamilton, who could hold their own alongside Schwarzenegger’s iconic eponymous robot, but My So-Called Life star Claire Danes put in a solid turn as the heroine of the third installment, 2003’s Rise of the Machines.
Despite being able to hold her own against both Arnie and the first female Terminator the T-X, Danes was not the first choice for the role. Or more accurately, Danes was technically the first choice of director Jonathan Mostow, but the actress' services could not be secured in time for filming and as a result, another actor was cast. Sophia Bush was the first to play Rise of the Machines' Kate Brewster, but shortly after filming began, it was soon felt Bush was too young for the role. As a result, Danes was consulted again and soon cast as Kate instead.
Although the number of scenes cut from Terminator 3's original script proves that the movie went through something of a tortured production process, denying the lead role to Bush still took an emotional toll on Mostow. The director admitted he had already wanted Danes but felt he had discovered a true talent in her short-lived replacement, which made the entire process feel all the more pointless when Danes was cast in the role after all. Mostow had this to say about Bush's recasting in a 2003 interview with Moviehole:
It was heartbreaking because initially I wanted Claire Danes and (…) it didn’t work out. So then I started casting for the part and I found this actress, Sophia Bush, who I thought was fabulous, and still do. And I cast her in it. I was more excited about casting her than I was anyone else in the movie. I thought I’d made a real find. And after a week of filming it became clear that she was too young… So I had to replace her and it was heart breaking because it was a huge break for her.
Fortunately, the Terminator 3: Rise of the Machines director need not have worried about Bush’s career potential, as the same year saw the actress nab a leading role in CW series One Tree Hill. Bush followed this with a string of teen movies such as John Tucker Must Die and Chalet Girl before returning to the small screen to star in shows like Chicago PD. Danes, meanwhile, has since enjoyed an illustrious career, although she never returned to the Terminator franchise after the third film received underwhelming reviews upon release.