I have white friends who have the Confederate flag on their license plates, and I have no issue with that if they see that as a matter of heritage. But I do not think it should ever fly over a state, city, county building, or school, for the simple reason that it represents secession from the Union.
It's a totally different spiel when I talk at Morehouse. But when I'm talking at MIT? At the University of Cincinnati? I'm telling white people, in order to stop systemic racism, you must first befriend, become a colleague of, get to know intimately, put yourself culturally in the framework of someone who doesn't look like you.