Joe Biden's age was his biggest liability — now Democrats can flip the script on arguments that Biden was too old to lead and apply them to Trump.
  • At 78 years old, former President Donald Trump is now the oldest nominee running for president.
  • Joe Biden, 81, dropped out of the race on Sunday and endorsed Vice President Kamala Harris, 59.
  • If she becomes the Democratic nominee, Harris’ age could be an advantage against Trump.