To be honest, I didn't include Maryland, Delaware, or West Virginia, which are south of the Mason-Dixon line, or Washington, D.C., but if you have ever been to any of those states, then you would know that they aren't really the South, since the people living there aren't Southerners, i.e, no Southern accent, Southern food, etc. They are no different from where I grew up in Southwest Pennsylvania, about 50 miles from the MD line, close to W. Va., and Maryland. Nothing remotely southern about the area. That Mason-Dixon line was a term coined over 150 years ago, and reflected the political divisions of that day and little else. W.Va. split from Va. at that time, because the people there were unwilling to side with the Southern views of the rest of Va. and chose to fight with the North in the Civil War.
Did not include Kentucky, Tennessee, or Missouri either. Kentucky and Tennesee are what we call the "Border States," meaning that they don't fall into the category of North or South. Basically, the people in those states are hillbillies and/or coal miners, and their urban cousins, which is a different breed of folks than Southerners, IMHO. I would say the area around Memphis is a bit Southern, but not Nashville or the rest of the state. Kentucky is more hillbilly than Tennesee. I don't dispute that the racial attitudes around there are not as progressive as the Northeast, West, Midwest or Eastern states, but it is still not the same as the South, attitudewise or otherwise.
Missouri is another state, that is a little bit Southern, but still not quite like the South. It is in between the Midwest and South, and is really an area which has its' own blend of Southern and Midwestern qualities, not exactly like anywhere else. There is some racism there, but I think they've made a great deal of progress(a lot of my ex's relatives were from St. Louis and smaller towns in MO). Remember Harry Truman? He was a quintessential Missourian, and, to me not at all like a Southerner. And he wasn't a racist, either. He is responsible for the first laws that began the path to equality for the African-American minority. He believed in giving every guy a fair break, regardless of race.
So, even if you included all of those states, that is still far from a majority of the population or the land area.
I really do know what you are referring to, the racism that is still below the surface in America. But it is the kind of "I don't want that guy living next door to me kind of racism. I don't want that guy dating my daughter racism. I think they are mostly lazy, no-goods, who want a free ride on welfare,and have low moral standards kind of racism." Those are the typical attitudes of the whites in areas where that kind of racism persists, and a certain amount of segregation persists. In the neighborhoods in PA, where I grew up, there are loads of nice houses for sale cheap. But, oddly enough, not a single black family living in that whole section of the metro area. A coincidence. Hardly! But yet, people who live there go to work in the city, and work side by side with blacks every day, and get along just fine with them, think they are nice people, don't hate them, and would never wish for any harm to come to them.
So, racism still exists in America. And it will for many years to come. But it has changed tremendously, and it is changing. The SF Bay Area is socially what you might call avant garde or cutting edge in the area of social progress. That is one of the reasons I settled here. Because I really couldn't stand the level of racism back East where I grew up, which was very in your face in those days. Although, even then, at the high school I went to, although the black kids were treated differently, they were never harassed, verbally assaulted or insulted, or openly treated in a bad way. It was all, as you say, below the surface. But not at all below the surface, when the black kids weren't present. And although, there was a lot of bad-mouthing of blacks, in general, going on, if someone said something specifically against a black kid, who was known to be a good kid, then you would see white kids, who kept their mouths shut when their friends were running down the black race, in general, that would speak up and say, "Hey, don't talk like that about him. I don't want to hear that kind of shit from you!!" Which would shut the first kid up, or else there would be a fight. And that was progress from the generation before.
Things are getting better in America, as far as racial problems go, IMHO. There is still a long way to go, but the progress made is remarkable when you look back to how it was only a few decades ago. SF is leading the way, but the rest of the country is moving in the right direction.