David Duke once was a grand wizard of the Ku Klux Klan.

You’ve heard of the KKK, right? They hate African-Americans, Asians, Latinos, non-Christians. They have burned crosses. They have killed people.

It’s an organization from which one cannot ever really escape, unless one does something demonstrable: such as disavow their previous association with the group; condemn its actions categorically.

David Duke — one-time Louisiana state legislator and gubernatorial candidate — hasn’t done that.

Duke, though, has endorsed Donald J. Trump’s platform on which he is standing as he runs for the Republican presidential nomination. He hasn’t endorsed Trump, per se. He just likes the things Trump is saying on the stump.

I’ll take a leap here to presume he means primarily the things Trump says about building a wall across our southern border and banning all Muslims from entering this country.

Trump, though, hasn’t distanced himself from the former grand wizard — Or is it grand dragon? I can’t keep those titles straight.

Instead, Trump says he doesn’t know anything about Duke.

Doesn’t know anything? Holy cow, man! He’s been in all the papers. Here’s how the New York Times reported it: “Well, just so you understand, I don’t know anything about David Duke,” Mr. Trump said in an interview with CNN. “I don’t know anything about what you’re even talking about with white supremacy or white supremacists.”

Trump needs to get out more, maybe.

The NYT went on: “I think he deserves a close look by those who believe the era of political correctness needs to come to an end,” Mr. Duke said, calling for a leader who would secure the border and dismantle the “Jewish controlled” financial industry.

As the conservative radio talk-show host Mark Levin said in a tweet: “Is it really that hard to disavow” a known Klansman?

One more item from the Times: “I don’t know David Duke,” (Trump) said. “I don’t believe I have ever met him. I’m pretty sure I didn’t meet him. And I just don’t know anything about him.”

Well, I’ve never met David Duke, either. Nor have millions of other Americans who detest the organization with which he is most closely associated.