South Carolina is considered a key state for any candidate running for POTUS. History has shown since the 80’s those who have won it sometimes went on to be their party’s nominee and win the general!
2000 George Bush / Al Gore (Democratic Caucus)| Bush went on to win general election
2004 George Bush (incumbent) / John Edwards | Kerry was DNC nomination lost to Bush in general election
2008 John McCain / Barack Obama | Obama went on to win general election
Its still anyones game, 3 states 3 winners