The tragedy in Charleston has prompted a lot of conversation and debate about the state of racism in this country. Authorities are still investigating what might have spurred the alleged shooter to commit such heinous acts.

According to our next guest, it was a sickness.

"This sickness," writes Joshua Dubois, "is the cancer of unacknowledged bias and supremacy."

And it is an affliction which does not merely affect one individual with a gun.

"We Need to Talk about White Culture" is the title of an essay which appears in the Daily Beast by Dubois, former head of the Office of Faith-Based and Neighborhood Partnerships at the White House.