President Biden's endorsement of Vice President Kamala Harris for the Democratic nomination could defuse the age question dogging the Democrats: Harris will be 60 on Inauguration Day — 22 years younger than Biden, Axios' April Rubin writes. Why it matters: Concerns over Biden's age and mental fitness were central to calls for his replacement as the Democratic nominee. Trump, at 78, becomes the oldest nominee in U.S. history if Harris or someone else younger than him succeeds Biden atop the Democratic ticket. 🔗 Read more at the link in our bio.