I can see why many Southerners, black ones in particular, don't like the implication that Southernness and the Confederate heritage are one and the same, because they're not. On the other hand, there are people who want to extirpate that completely and want folks to spit on the graves of their ancestors.
Southerners are also like ethnic groups in that they have a sense of group identity.
Their prejudice allowed white Southerners to look the other way when blacks were denied their most basic human rights, and it encouraged the worst of them to engage in unspeakable acts of cruelty and violence.
For generations, even many otherwise decent white Southerners learned to despise black people.
The Mormons' passage from bugbears of the Republican Party to its stalwarts may be analogized to a similar move among middle-class white Southerners, to whom the Republican Party was anathema until the 1970s and '80s, after which it became almost the sole representative.
There is racism all over the United States. Most Southerners I know, we definitely find ourselves defending our heritage.
It takes a willful disregard of history to appreciate how white Southerners could look at the Confederate battle flag and see states' rights or a way of life or a tradition - and not one human being whipping another, which was a common occurrence.