Last week at this time, I was in Israel.The idea that a German would say, you know, that thing we did called the Holocaust, that was wrong, but I respect the courage of my Nazi ancestors. That wouldn't happen.

(Joe Raedle/Getty Images) A sign equating the Confederate flag with the Nazi flag at a protest in support of a Confederate flag's removal from the South Carolina capitol grounds.

It has been 150 years since the Civil War officially ended, but take a trip to certain regions in the South and you may get a different impression.

Especially since last week's shooting in South Carolina, the Confederate battle flag has become an iconic and often unwelcome reminder that race relations in the US still face a staggering uphill battle.

But some people still wave the flag with pride, and Georgetown University law professor Paul Butler has some words for those people.

On a Monday episode of "The Diane Rehm Show," a caller said her Confederate ancestors deserved respect, even though the Confederate flag represented "racial hatred."

To which Butler replied:

I have no respect for your ancestors. As far as your ancestors are concerned, I shouldn't be a law professor at Georgetown. I should be a slave. That's why they fought that war. I don't understand what it means to be proud of a legacy of terrorism and violence.

Last week at this time, I was in Israel. The idea that a German would say, you know, that thing we did called the Holocaust, that was wrong, but I respect the courage of my Nazi ancestors. That wouldn't happen.

The reason people can say what you said in the United States, is because, again, black life just doesn't matter to a lot of people.

Butler isn't alone in that bleak assessment.

Just ask the students at the University of Texas, who recently spray-painted "Black Lives Matter" on a Confederate statue.