When African American people were slaves they were treated horrible. Now that racism is no that bad, people say it "doesn't exist anymore" or that "its not that bad".
But, if you do so happen to insult someone for their race in public, you will be hated on. This just brings into view that racism doesn't always happen in public- therefore it is not fully taken care of.
Everybody has a different view on racism in the world. Some people think its okay some not. This "Makes the best of friends begin to fight" because they may or may not be against racism.