In 1972 he was elected to the U.S. Senate as a member of the Democratic Party. He went on to win reelection six times and became Delaware’s longest-serving senator (1973–2009). As a senator, Biden focused on foreign relations, criminal justice, and drug policy. After two unsuccessful bids for the Democratic presidential nomination (1988, 2008), he was Barack Obama’s running mate in 2008 and served two terms (2009–17) as vice president. In 2020 Biden became the Democratic presidential nominee, and he chose Kamala Harris, an African American senator, as his running mate.