Vice President Kamala Harris appears to have energized Democrats in the early days of her candidacy, with the surge in warm feelings extending across multiple groups, including some key Democratic constituencies that had been tepid about President Joe Biden.
this sounds a bit like survivorship bias. Because the outcome has been good does not mean risks where less likely. That being said for myself it was not about risk per se but more I just liked him over any realistic possibility including harris. that being said I see little difference between voting for harris as vice president or potential president given the age and directly for president. so ultimately its fine.