President Barack Obama has recently tweeted that children are not born racist. Unfortunately, in America some learn to become racist.
One might assume that the people of America would share a collective memory. They should remember the prejudice and violence aimed at black Americans from 1619 through the Civil Rights Movement to the present day. For black people, this collective memory includes the images of night-time torches, burning crosses, and KKK rhetoric about protecting the "purity of the white race" and the supposed "inferiority of the colored races." Donald Trump clearly does not share this collective memory when he suggests that there is "racism on both sides."
On NPR NewsHour, Leonard Pitts, Jr., an excellent journalist for the Miami Herald put it very well: White Americans think that being called a "racist" means they are not nice people. They want to be thought of as nice, so if you call them racist, it affects the quality of their day.
To black Americans, however, racism affects not just the quality of their day but the quality of their lives. In fact, as we have seen in police shootings of black men, it may even cost them their lives.