Good morning, anons.
The 2008 United States Senate election in Delaware was held on November 4, 2008. Incumbent Democratic U.S. Senator Joe Biden won re-election to a seventh term and won the Vice Presidency of the United States on the same day. Biden took his oath of office in the Senate chamber with the rest of his colleagues on January 6, 2009, but resigned his seat on January 15, 2009, and assumed the Vice Presidency five days later.
https://en.wikipedia.org/wiki/2008_United_States_Senate_election_in_Delaware