If Democratic presidential front-runner Hillary Clinton were to lose next week's California primary by a wide margin, there could be room for Vice President Joe Biden to make a bid for the nomination, said Walter Isaacson, former CNN chief and TIME magazine editor.
Under that scenario, Biden would have a 20 percent chance, Isaacson told CNBC's "Squawk Box" on Thursday, saying he also could see as an outside possibility 2004 Democratic presidential nominee John Kerry, who succeeded Clinton as President Barack Obama's secretary of state.
Biden, after much consideration, decided in October not to run for the White House again. The vice president, along with Clinton, ran for the nomination in 2008. They both lost out to Obama, who later chose Biden as his running mate.
"If Hillary Clinton loses California in a serious way, it shows she's not connecting with the tenor of the times, especially people's frustration and anger," said Isaacson.