Biden was surprised by the friendly tone of the letter left for him in 2021 by Trump, who left the White House. This is what the "New York Times" reported, citing excerpts from the upcoming memoirs of the former US president, Promise me, America.
As mentioned, Trump did not criticize Biden and did not try to challenge the results of the presidential election. In this context, Biden wrote that it seemed to him as if "there were two Donald Trumps".