If Joe Biden steps aside, who takes his place?

By the time this column is published, President Joe Biden may have announced that he is pulling out of the 2024 presidential campaign. There is simply no other path forward for the incumbent president. The entire country now knows what audiences of Fox News and other right-leaning news organizations have known for some time: Biden is in rapid decline and cannot possibly serve for another four years. 

A new CBS/YouGov poll conducted after the debate showed that 72% of the public no longer...