What's the controversy over Donald Trump and the KKK?

After attaining the endorsement of a former Ku Klux Klan leader, on Monday the presidential candidate distanced himself from the white supremacist group. 

[Update: On Monday, Donald Trump told NBC's "Today" that he was given a "very bad earpiece" for Sunday's interview and that he "disavowed David Duke all weekend long on Facebook and on Twitter."]

Repeatedly evading the question, Donald Trump refused to condemn his endorsement from a former Ku Klux Klan leader in an interview Sunday morning.

Last Wednesday, radio host David Duke, a white nationalist and a former KKK grand wizard, told his audience that voting for any candidate other than Donald Trump “is really treason to your heritage.”

But since this de facto endorsement, Mr. Trump has been vague about renouncing it.

"Just so you understand, I don't know anything about David Duke, OK?" he told CNN's Jake Tapper on "State of the Union” Sunday.

According to the news station, the real estate mogul was asked three times whether he would like to disavow his support from white supremacist groups.

“I mean, I don’t know what group you’re talking about,” he said. “You wouldn’t want me to condemn a group that I know nothing about. I’d have to look. If you would send me a list of the groups, I will do research on them, and certainly I would disavow if I thought that there was something wrong.”

To which Mr. Tapper said, “the Ku Klux Klan.”

Without addressing the matter head-on, Trump also never named the KKK explicitly in his answers. His evasion continues:

Trump: But you may have some groups in there that are totally fine, and it would be very unfair. So, give me a list of groups and I’ll let you know.

Tapper: Okay, I’m just talking about David Duke and the Ku Klux Klan here but…

Trump: Honestly, I don’t know David Duke. I don’t believe I’ve ever met him. I’m pretty sure I didn’t meet him, and I just don’t know anything about him.

But as reported by The New York Times in 2000, Trump did know Mr. Duke back then.

Condemning the political group, the Reform Party, Trump cited Duke as an unwelcomed supporter. "The Reform Party now includes a Klansman, Mr. Duke, a neo-Nazi, Mr. Buchanan, and a communist, Ms. Fulani. This is not company I wish to keep," he said in a statement

Trump also addressed the endorsement Friday. As The Hill reported, Trump quickly brushed off the question.

“I didn't even know he endorsed me," the GOP presidential front runner said.

"David Duke endorsed me? OK, alright. I disavow, OK?,” he added.

Since his ambiguous comments Sunday, his opponents have taken the opportunity to criticize him.

“Really sad,” Ted Cruz tweeted. “[Donald Trump] you're better than this. We should all agree, racism is wrong, KKK is abhorrent.”

Marco Rubio, a Florida Senator and another presidential contender, also posted on Twitter. “We cannot be a party that nominates someone who refuses to condemn white supremacists and the Ku Klux Klan,” he wrote.

The Atlantic’s Yoni Appelbaum suggests that Trump’s dubious responses may have something to do with his family’s possible affiliation with the KKK.

In a 1927 Memorial Day parade in Queens, New York City, seven men in white robes and hoods were arrested. Six of them were charged, and one was released. The latter was Fred Trump – a man with the same name and address as Donald Trump’s father.