Elisabeth Shue took over the role of Marty's girlfriend Jennifer in the Back to the Future sequels, and here's why that decision was made. In the first Robert Zemeckis film, he brought together a talented cast that included Michael J. Fox as Marty McFly and Christopher Lloyd as Dr. Emmett Brown, with Lea Thompson and Crispin Glover as Marty's parents. But Back to the Future also had Claudia Wells play the role of Marty's girlfriend, Jennifer.
Undoubtedly Wells' biggest role in her career, her time playing Jennifer was cut short as a not-so-rare case of recasting happened. Wells was replaced by Elisabeth Shue in Back to the Future II, a move that many may not have noticed as the sequel reshot the ending of the first film with Shue to serve as its opening. At the time, Shue was a rising star after roles in The Karate Kid, Adventures in Babysitting, and Cocktail.
So did Zemeckis choose to recast the role of Jennifer just to get a bigger star like Shue involved? No, and the reason behind the recasting didn't have any drama behind it either. The truth is actually much sadder. When it came time for the Back to the Future sequels to begin, Wells had to drop out of the role to take care of her mother. Wells' mom had recently been diagnosed with cancer and she decided to be with her instead of returning to Back to the Future.
Even though Wells' time as Jennifer was cut short, she almost didn't get a chance to play the character at all. After being initially cast in the role, she was forced to drop out after a pilot for a new show on ABC was picked up for a full series. Melora Hardin was set to play the part instead, but Wells was able to return to the project only after another recasting occurred. Famously, Back to the Future originally starred Eric Stoltz as Marty McFly, but he was dismissed from the role after five weeks of filming. Once the decision was made for Michael J. Fox to take over the part, Wells was freed up to play Jennifer as originally intended.
Although tragic circumstances led to Wells having to walk away from the Back to the Future franchise again, she has had the opportunity to return to the role in the years since. Telltale Games made Back to the Future into a video game in 2011 and had Wells voice Jennifer for a few episodes. She also reprised her role as an adult Jennifer in a Back to the 2015 Future short film. While small parts, at least these opportunities gave Wells a chance to play her Back to the Future character a couple more times.