Joe Biden told Stephen Colbert that he's disappointed GOP Sen.
Lindsey Graham has not recognized him as the winner of the 2020 election.
"Lindsey's been a personal disappointment because I was a personal friend of his," Biden said.
Business Insider reports that Graham was once a sharp critic of President Donald Trump.
Now, has supports the president's longshot legal efforts to overturn the election results.
The South Carolina Republican was previously a close friend of Biden's.
