GREENVILLE, S.C.—Joe Biden will try to slow Bernie Sanders’s rise in Saturday’s primary in South Carolina and hang onto his longtime lead among black Democrats, some of whom say they are considering other candidates.

This state is the first in the primary-voting calendar where black voters make up a majority of the Democratic electorate. In 2016, roughly 60% of primary voters were black, according to exit polls. That year, Democrat Hillary Clinton won a decisive victory that foreshadowed Mr. Sanders’ lackluster performance…

Read More