Well until the 1960s, the members of the black community couldn't even attend the same schools, use the same bathrooms, or vote in the same elections as members

Well until the 1960s, the members of the black community couldn't even attend the same schools, use the same bathrooms, or vote in the same elections as members of the white community. Now although the laws have changed, people who were previosuly racist in the 1960s did not simply die out overnight. They had no real reason to abandon their views, so they simply maintained them and passed it down to their children. Unless they or their children actively uprooted their baises, you'll find there are still plenty of people who are biased today.