Jon Lieber, head of Eurasia Group's coverage of political and policy developments in Washington, DC, shares his analysis on US politics:

Are America's political leaders too old?

A new poll this week suggests the Democratic voters would be very open to alternatives to President Joe Biden in the 2024 election cycle. Many Democrats, including Biden himself, argue that he offers their best chance to defeat our Republican challengers in two years, particularly if that challenger is former President Donald Trump. But it's very clear through polling leaks and voter interviews, that there is a high degree of concern about one major issue, President Biden's age. Among the 64% of Democratic primary voters in the New York Times poll who said they would prefer a candidate other than Joe Biden, 33%, a plurality, said it was because of his age. Biden is already the oldest president in history, and if he wins another term, he would be 82 on Inauguration Day, and 86 when he finishes his second term.