There are some really great takes on South Carolina politics over at the Times, Room For Debate. This one by Thomas Schaller is really rich on the history:
Thomas Jefferson removed condemnations of slavery from the Declaration of Independence to appease South Carolinian slaveholders. State loyalists helped the British recapture the state in 1780 from the patriots. By 1828, state icon and Vice President John C. Calhoun was advocating state "nullification" of federal powers.
In 1860, South Carolina became the first state to secede -- and even threatened to secede from the Confederacy because the other southern states refused to re-open the slave trade. In 1856, on the Senate floor Congressman Preston Brooks bloodied an abolitionist senator with a cane.Well into the 20th century, South Carolina's black citizens observed the Fourth of July mostly alone; the vast majority of whites preferred instead to celebrate Confederate Memorial Day. In 1920, the state legislature rejected the women's suffrage amendment, finally ratifying it a half century later.
Lots of meat in there (like ratifying women's suffrage in 1970.) But I am thinking about that Fourth of July point. It reminds me of some of the research David Blight has done which argues that the first Memorial Day was actually celebrated by blacks in South Carolina.
One of the great tragedies of the past half century or so, is how patriotism has been coopted by people who claim the Confederate flag, while black leaders, from King to Obama, are dismissed as communists/socialists and now Hitlerite. These are people whose heroes routinely flouted the federal government and assaulted black troops carrying the Union flag.