Imagine the following scenario: On the 9th of January 2024 in the morning we wake up to news that President of the USA Joe Biden suffered a stroke and died in White House. The administration confirms that the death was entirely natural and no third party contributed to it. Even before the news reach all TV stations another one breaks: Former president of the USA Donald Trump has suffered a cardiac arrest and died in his residence in Mar a Lago. Early reports claim that the site was secure and no malicious actor could reasonably reach Mr. Trump so the death is most likely natural.
What happens then?
Kamala Harris becomes president and both primaries will elect someone.
I’m not sure anyone on the dem side would primary Harris, however. If she is primaried, Gavin Newsome would probably be sworn in about this time next year.
On edit: jmho