Harlem church , CNN host African-American debate morning . Front-runners vying for African-American voters ahead of South Carolina primary . Sen. Barack Obama visits former church of the Rev . Hillary Clinton , Jr. in Atlanta . Sen. Barack picks up pastor 's endorsement at Harlem church .
Congressional Black Caucus Institute , CNN host Democratic debate tonight . Front-runners vying for African-American voters ahead of South Carolina primary . Sen. Barack Obama visits former church of the Rev . Martin Luther King , Jr. in Atlanta . Sen. Hillary Clinton picks up pastor 's endorsement at Harlem church .