Successful predictions of unlikely candidates becoming US president are rare but two stand out. In 1968, presidential candidate Robert F. Kennedy predicted that a 'Negro' would become president in 40 years and it happened with Barack Obama in 2008. Then in October 1989, former US President Gerald Ford responded to a question from a young girl that a woman would become president by way of the vice presidency and it looks as it might happen with US Vice-President Kamala Harris.
When in 2000 US presidential candidate Joe Biden picked California Senator Harris to be his running mate, he opened many possibilities which included incapacitation of the president, very close to the way Ford predicted. Age and infirmity have knocked Biden out of the 2024 presidential candidacy and Harris has stepped in.