Biden lands key endorsement three days before South Carolina presidential contest

Democratic U.S. presidential candidate and former U.S. Vice President Joe Biden makes his way to the microphone at the start of a campaign event in Georgetown, South Carolina, U.S., February 26, 2020. REUTERS/Elizabeth Frantz

CHARLESTON, S.C. (Reuters) - Democratic presidential contender Joe Biden won the endorsement of an influential black congressman from South Carolina on Wednesday, three days before the state's primary where he is competing with national front-runner Bernie Sanders for the crucial African-American vote.

Recent opinion polls show Biden, once the leading candidate in the race to be the Democratic candidate in November, losing ground nationally to the surging Sanders among black voters.