Editor's Note: (Dorothy A. Brown is a law professor at Emory University. The views expressed in this commentary are solely those of the author. View more opinion articles on CNN.)

(CNN) President Donald Trump wants NASA to go to Mars, but his Treasury secretary can't figure out how to put Harriet Tubman on the $20 bill?

Dorothy A. Brown

We recently learned that the planned Harriet Tubman currency — which was slated to replace the $20 Andrew Jackson bill in time for the 2020 centennial of the 19th Amendment — can't be rolled out until 2028. This, even though the engraving plate for it was completed "as recently as May 2018" a Treasury Department employee told the New York Times. The employee also said the design "appeared to be far along in the process," according to the Times. Apparently so — as we all saw a picture of it leaked to the press.

Pay no attention to that, Treasury Secretary Steven Mnuchin has indicated. There are technical difficulties and they will persist until long after President Trump leaves office, he tells us. We'll pause here to note that the plan for the Tubman bill originated with Trump's predecessor, the first black President of the United States. President Barack Obama referred to Harriet Tubman — an abolitionist who led enslaved people to freedom via the Underground Railroad — as "an American hero ... [who] fought tirelessly for the Union cause, for the rights of enslaved people, for the rights of women, and for the rights of all."

In 2016, candidate Trump told NBC that stripping his favorite president, the populist and slave owner, Andrew Jackson, from the $20 bill was "pure political correctness." He suggested that Tubman be bumped to the $2 bill, which is no longer printed.

In the scheme of things, this is not the worst thing the President or his administration has done to disrespect a source of black pride, but it is telling. This President's belief in white supremacy knows no bounds and perhaps a better descriptor would be to start referring to him as our white-supremacist-in-chief.

He has claimed that he is the "least racist person" we know. Yet starting in 1973 we learned otherwise when the Justice Department under President Richard Nixon sued the Trump Management Corporation for refusing to rent apartments to blacks, among other things. (Trump settled the suit without an admission of guilt.)

Next up let's take his involvement in the Central Park jogger case. I was living in New York at the time and the case of those innocent youngsters — Antron McCray, Kevin Richardson, Yusef Salaam, Raymond Santana, and Korey Wise — left an indelible mark. I remember Donald Trump taking out full page ads in newspapers to advocate for the death penalty.

In 2014 the Exonerated Five received a $41 million settlement from New York because another man confessed and had the DNA to prove it. Yet Donald Trump stated in 2016 in an interview with CNN that he still believed their guilt. Facts and simple justice do not get in the way of white supremacy, it just bulldozes over anything that would challenge the notion that whites belong at the top and blacks at the bottom.

Some could argue that Trump started his run for President off birtherism claims and his questioning of President Obama's American citizenship. After conceding that Obama was an American citizen, he reportedly resumed raising the question in 2017.

Americans don't need to scratch hard on the surface of this presidency to find the poorly concealed bigotry beneath. But who else knows this about the current occupant of the White House? The Russians. And this brings me to the most dangerous harm unleashed on our country by our white supremacist-in-chief — and it affects all of us. Intelligence reports describe Russian efforts to help elect Trump by targeting potential black voters to ultimately get them to stay away from the polls. White supremacy is a national security issue.

There's a direct connection between Trump's fair housing lawsuit, the Exonerated 5, his election as President, his administration's push for a cooked-up Census question designed to undercount people of color and help white Republican candidates win, to now, where his administration is effectively banning the likeness of Harriet Tubman — a black woman and towering figure in American history — from the $20 bill. There is apparently no issue — large or small — involving the rights and advancement of people of color that the President won't weigh in on, with his thumb on the scale.

I shudder to think what's next.