COLUMBIA, S.C. Busy in Nevada before Saturday’s caucus vote, former Vice President Joe Biden is sending one of his top surrogates down to South Carolina less than two weeks ahead of the state’s Democratic presidential primary. Former U.S. Secretary of State John Kerry, who in 2004 ran for president as the Democratic nominee, will join Biden’s sister, Valerie Biden Owens, and Biden’s senior campaign advisor Symone Sanders on Biden’s “Soul of the Nation” bus tour through the state.