Joe Biden formally accepted the Democratic presidential nomination on Thursday, a position he has sought for more than 30 years and through three White House bids. His running mate, California Sen. Kamala Harris, accepted the vice-presidential nomination on Wednesday. Biden served three decades as a senator from Delaware before being tapped as President Barack Obama’s vice president. He first ran for president in 1988 and tried again in 2008 before launching his 2020 campaign last year.