To European eyes this is just an old flag from the Civil War, to American eyes this is still an open wound and the debate on various websites covering this is already more virulent and nasty than I have ever seen.
Foreshadowing events later (I'm sure) half of the Republican response is "it must be a Liberal plant" and the other half is "what's wrong with the Confederate flag anyway?" (Answer : it is the symbol of military revolt against the US government and institutional racism and slavery).
It will be very interesting to see how the hyper patriots on the American right explain how it is that their core support seeks to undermine the United States itself. I think the old Republican party as we know it received a mortal wound at this event.
Neo-Confederate is a term used by some academics and political activists to describe the views of various groups and individuals who have a positive belief system concerning the historical experience of the Confederate States of America, the Southern secession, and the Southern United States.