The South Carolina primary is a critical springboard for Super Tuesday

Bernie Sanders is coming in hot to the South Carolina primary — the last early contest before Super Tuesday — where a win could make or break former Vice President Joe Biden.

“If Joe Biden wins by a small margin, then I think his campaign is on life support,” says Anton Gunn, Barack Obama’s 2008 South Carolina political director. “If he comes in second or worse, I think he’s done.”

South Carolina, unlike Iowa and New Hampshire, has an incredibly diverse Democratic electorate: Sixty percent of the state’s Democratic voters...