Whatever virtues or flaws one might attribute to particular presidential aspirants, one characteristic that must be considered when selecting a candidate is age. Two of the leading Democratic presidential hopefuls are, to put it delicately, old. Joe Biden was born November 20, 1942; Bernie Sanders was born October 8, 1941. Were one of them to be elected president in 2020, he would be 78 or 79 years old, respectively, when inaugurated and would become the oldest inaugurated president. (Donald Trump currently holds that record, having been 70 on inauguration day.) Were that person to serve two terms—Democrats surely want the next president to be a Democrat and to be re-elected in 2024—he would be 86 or 87 years old, respectively, upon leaving office. At such time, his age would be greater than his actuarial life expectancy.
It need hardly be said that, as one advances in age, one is increasingly likely to suffer medical issues, serious disabilities, or death. Were Democrats to select either Biden or Sanders as their standard bearer in 2020, the selection of a vice-presidential candidate would become more important than usual, as that person would have a significant likelihood of becoming President of the United States.
I believe that, on the basis of age alone, neither Biden nor Sanders is a wise (and perhaps not even a viable) choice as the Democratic nominee.
And as much as I like Elizabeth Warren, she, having been born on June 22, 1949, is only three years younger than Donald Trump. If she assumed office on January 20, 2021, even she would displace the incumbent as the oldest president upon inauguration.
Even were Republicans to ignore the age factor during the 2020 campaign, should Biden, Sanders, or even Warren gets the Democratic nomination, Democrats would still be making a serious error in selecting such an elderly candidate.
Democrats have a gaggle of younger, attractive presidential aspirants. They should select one of them as their standard bearer.