When Biden was first elected as a Senator of the United States in 1972(!) he wasn’t actually old enough to be one. His 30th birthday occurred before the swearing-in ceremony and ABC News decided to celebrate both his birthday and his election as the youngest-ever Senator. In this interview with Bob Clark you can see the young senator giving the elderly president a message about the “seniority system” (around 1.30 minutes in) where he says it “has many more drawbacks than merits”. Hands up who wishes he’d have listened to himself.
1972: Makes history as youngest senator
2020: Makes history as oldest president