To put a more cynical twist on it for those less emotionally inclined, the contradiction between a US that believes in equality between humans and 30% of its population suffering from the legacy of slavery will eventually tear US society apart. It doesn't matter if you don't personally feel guilt or the need to fix this racial inequality, if this issue doesn't get fixed there may not be a US in the future. Responsibility means dealing with the problems of life even if you don't want to and wish it didn't exist before those problems spiral out of control.