Donald Trump made waves on Sunday by failing to denounce the Ku Klux Klan and former grand wizard David Duke, who has said whites who don't support Trump are race traitors.

On Monday, Trump tried to blame his hesitance on a "bad earpiece." But that is a blatant lie, and here's how we know.

I rewatched the CNN segment with Jake Tapper (here's the video and transcript), and at no point during the nine-minute interview does Trump say he has trouble hearing a question, stick his finger in his ear to adjust his earpiece, or make any other facial expression suggesting he was having trouble hearing.

During the interview, Trump responded to questions about the Chris Christie endorsement, the #neverTrump movement, and his tax returns and financials before getting to the KKK part. Trump reacted to Tapper without problem.

During Trump's infamous response, he managed to state, "I don't know anything about David Duke" and "I know nothing about David Duke. I know nothing about white supremacists."

So, Trump was hearing well enough to deny several times that he knew anything about Duke.

Also, it isn't as if Trump is some "aw shucks" newbie to television. As he reminds us over and over, he had a hit show on NBC for years. He's spent decades in the spotlight and has built his campaign in large part around his ability to manipulate the media. Before anybody goes live on TV, they have to go through audio tests to make sure they can hear. If the earpiece was as bad as he claimed, then he would have had ample time to report the technical problem so that it could be taken care of before going live.

In addition to this, we also know that Trump has no problem lying.