Nope, I have lived all over and the south is especially hot with rampant racism. It exists everywhere but it has continued to be cultivated to a very high degree in the south.
All I can say is that my experience has been different. Very different.
Racism is everywhere. Some places it's more hidden; some places it's more blatant; and some places it's simply more.
My dad was in the military, and we lived all over. In fact, my dad was from the South, and yes, he was very racist.
I'm white, and during my college days up North I had a black roommate. His family was moving back to Alabama. According to them, the Southern racists were more honest because they told you to your face what they thought of you; the Northern racists waited until your back was turned.
I then joined the military, and I lived all over, all over again, and in 10 different countries. My wife is Asian. In my experience, the most racist place I've ever lived was in Hawaii. The second most racist place was Richmond, VA.
We now live in the Deep South (and no, not Florida). Is there racism here? Yep. But I see more black-white couples here than any place in my entire life. And I see A LOT more inter-racial interactions here than any place in my entire life. Most of the other places I've been to have almost no inter-racial interactions.
As for white Dems being racists, I'm sure there are some. But preferring Hillary over Obama doesn't indicate racism. Frankly, Obama strikes me as a man of surface-level intellect. He obviously isn't a deep thinker, and he doesn't seem to process information through an internal B.S. filter. For example, he claimed that Kansas tornadoes killed 10,000 people when in fact the death toll was 12. A person with a working B.S. filter would have questioned a death toll of 10,000, which is nearly twice as big as our worst natural disaster (the 1900 Galveston hurricane). And there are lots of other examples of shallow thinking.
Basically, he's a rubber stamp. When he says, "Yes, we can," he's speaking for his controllers. I can see a lot of Hillary supporters wanting someone with more depth. No racism in that.
I can also see a lot of blue collar Dem voters who aren't very happy with being mocked for clinging to their religion and guns out of bitter frustration. I can see a lot of them preferring Hillary. No racism in that either.