If Joe continues to poll losing to Trump, and RFKJ continues to close the gap on Biden, Democrats will recruit Newsome. The worst case scenario for the Democrats, is a moderate like RFKJ running against Trump, because no matter who then wins, they lose.
What I want to see if these polls continue on, is how the Democrats side step Harris as the standard bearer. That will be a political move for the ages, if this scenario unfolds. Oh sure, she will make a statement about more family time, etc to make it plausible; but nobody is going to believe it, especially the Black community.