Age has become a key issue of the 2024 presidential race, with the two front-runners being among the oldest major party candidates in history. President Joe Biden, 81, is seeking reelection as the oldest president in U.S. history.

Republicans, despite likely running former President Donald Trump, 77, have focused on Biden’s age as an issue, citing repeated gaffes and special counsel Robert Hur’s report that noted the president’s alleged memory problems. Democrats have cried foul on the attacks on age, but they have made age an issue of several campaigns with GOP candidates who were younger than Biden. Here are three times Democrats made age an issue about GOP presidential candidates.