The ID law is subject to DOJ review and approval under the Federal Voting Rights Act. SC's voter ID law will never stand.
I believe that provision of the Federal Voting Rights Act is applicable only to states which have had a history of Jim Crow, i.e., the states of the Old Confederacy and perhaps some border states.
My feeling is that we've reached a point in our history where we can safely and fairly repeal that specific provision, but you can bet that the Obama-Holder DOJ will attempt to block the SC ID law. In that event, I believe that SC could file suit against the DOJ in federal court, and that the AG of SC has already announced the intention to do so.