Southerners today are not the same people as the ones in the days of slavery. When they left the Democrat party it wasn't because of racial issues because unlike Democrats of today, no one else obsesses over race. The much, much, much bigger concern back then was all about Communism. People used to build underground shelters. It wasn't so they would never have to see a black person, it was because of the Cold War and the threat of nuclear annihilation. The Democrat were busy trying to become Communists and so everyone who believed in freedom ran away from that party. Those who stayed were communists, socialists, Neo-Nazis, fascists and a whole lot of people who weren't paying any attention. Because it was the communists, socialists, Neo-Nazis and fascists who made up the Progressive movement of the early 20th century. Those Democrats openly and publicly praised Hitler, Stalin and Mussolini. Those Democrats are the ones who make up today's Democrat party.
So the Confederate battle flag is just a flag. It no longer symbolizes the war between the states because that war has long ended. It does not symbolize racism, unless you are a race obsessed Democrat who is on a constant witch hunt to trying to find a racist anywhere they can, so that they can feel good about themselves. Yes, the KKK used it but that makes no difference because the KKK also uses the U.S flag and a bunch of other stuff that we just take for granted. Just because a Klansman owns a TV does not mean that TV's are racist. The same with the flag. It is a really hard concept for leftists to understand because they are so obsessed with race that that is all they can ever see when they see that flag.
But here's another really hard concept for the left to grasp, freedom. This is (or was) the land of the free. That means if I want to fly a Confederate battle flag in front of my house then that is my right. I would not be hurting anyone, I am not supporting the return of the CSA. It isn't even the flag of the CSA. It would just mean that I am proud of where I was born. Nothing more and nothing less. That all being said, I do not fly a Confederate battle flag in front of my house because of left. You have turned that flag into a flag of racism, even some conservatives think it means racism because of your party's obsession with race, which, by the way, IS racist.