Born in 1942, Biden was among the teenagers who heard John F. Kennedy declare that the “torch” had passed to a “new generation.” That was in 1961. Biden’s first run for president was in 1988. At the inauguration in 2021, the age gap between Biden and his vice president, Kamala Harris, was so large that it was hard not to think of the presidential and vice presidential couples as a family group—adult children and spry elderly parents.