Joe Biden is 80 and not very popular. Donald Trump is 77, not very popular, and facing four indictments. The possibility that one or both parties might replace either man before they secured their respective presidential nomination—or afterward—because of health, death, or legal conviction is worth considering if only because weird stuff happens all the time in American politics. Twenty-three years ago, Americans had to take a crash course in Florida election law, such as what distinguished hanging chads in Broward County versus butterfly ballots in Leon County, as the 2000 presidential...…Joe Biden is 80 and not very popular. Donald Trump is 77, not very popular, and facing four indictments. The possibility that one or both parties might replace either man before they secured their respective presidential nomination—or afterward—because of health, death, or legal conviction is worth considering if only because weird stuff happens all the time in American politics. Twenty-three years ago, Americans had to take a crash course in Florida election law, such as what distinguished hanging chads in Broward County versus butterfly ballots in Leon County, as the 2000 presidential...WW…