GEOFF BENNETT: President Trump says the U.S. government is poised to accept an airplane from Qatar valued at nearly $400 million.

He explained on social media: "The Defense Department is getting a gift free of charge of a 747 aircraft to replace the 40-year-old Air Force One."

The announcement has raised ethical and national security concern.

We're joined now by Kathleen Clark, an expert in legal and government ethics and professor at Washington University School of Law in St. Louis.

Thanks for being here.

KATHLEEN CLARK, Washington University of Saint Louis: Thank you for having me.

GEOFF BENNETT: So, President Trump today, he called the offer of this airplane, he said it was a nice gesture that would be stupid to turn down.

And the attorney general, Pam Bondi, reportedly said in a memo that this was perfectly legal because it was a donation.

Bondi, we should say, worked as a foreign lobbyist for Qatar.

What questions does all of this raise for you?

KATHLEEN CLARK, Washington University in St. Louis School of Law: This appears to be an illegal, unconstitutional payoff from a foreign government to the president at a scale we actually have never seen, on the order of $400 million.

GEOFF BENNETT: You use the word payoff.

Why?

KATHLEEN CLARK: I use the word payoff because it implies corruption, and that's what we're talking about here.

Our founders put into our Constitution a prohibition on government officials, including the president, accepting payments, gifts from foreign governments.

They didn't want our government officials to have tainted - - to be tainted by this kind of conflict of interest.

And that's why the Constitution includes this Emoluments Clause and says that the president and others cannot accept such gifts, unless Congress specifically authorizes it.

GEOFF BENNETT: What about the level of transparency?

The administration says this is all happening out in the open, there should be no concerns.

Does that in any way counteract the perceived conflict of interest?

KATHLEEN CLARK: Not at all.

This is not a situation where disclosure cures the crime or disclosure cures the conflict.

Our founders didn't say the president and others cannot accept gifts from foreign potentates unless they disclose them.

They said the president and others cannot accept gifts from foreign potentates unless Congress affirmatively consents.

GEOFF BENNETT: The president said that this plane will be a gift to the Department of Defense and once he's no longer in office it will be decommissioned, then go to the Trump Library.

He says there's precedent for this because Ronald Reagan did it and there's a decommissioned Air Force One at Reagan's presidential library.

What do you make of that?

KATHLEEN CLARK: There is no precedent that I'm aware of, of a president accepting a gift on this scale from a foreign government.

And the fact that he's doing so while laundering it through the Department of Defense and using it as the equivalent of Air Force One for a couple of years does not in any way diminish the corrupt nature of this deal.

GEOFF BENNETT: What about the national security concerns?

Air Force One is a flying fortress for the president of the United States.

If this were to move forward the U.S. Air Force would, of course, have to receive this plane.

They'd have to basically strip it down, search for surveillance devices, and then rebuild it to fit the needs of transporting a president.

The idea that an Air Force One would originate for from a foreign government, what questions does that raise?

KATHLEEN CLARK: It raises all sorts of questions about electronic security.

But even in the way you phrase that question, it undermines the claim that this is actually some kind of bargain for the federal government.

It's not that the federal government is getting the equivalent of Air Force One for free.

They're getting an airplane frame that they will then have to, as you say, strip down and examine for countermeasures, electronic countermeasures, and then provide it with the same kind of capacity that our Air Force One jets have.

This is no bargain.

It's not even a corrupt bargain.

It's just corrupt.

GEOFF BENNETT: If this moves forward, what precedent does it set, not just for President Trump, but for future presidents?

KATHLEEN CLARK: I'd say that President Trump thinks he's going to get away with this.

And if he does, we can anticipate his convincing some other foreign government to provide more lavish gifts to him in the future.

I won't posit what the future holds past the Trump presidency, but I suspect that this will not be the last time that President Trump attempts to violate the Emoluments Clause.

GEOFF BENNETT: So, this administration, presented with this offer, should just say, thanks, but no thanks?

KATHLEEN CLARK: Absolutely, yes.

Be gracious when someone offers a gift, and refuse it where it would be corrupt, as this one would.

GEOFF BENNETT: Kathleen Clark, thank you so much for your insights.

KATHLEEN CLARK: Thank you.