Ben Carson, the surgeon turned politician who has improbably been tapped by US president-elect Donald Trump to lead the Department of Housing and Urban Development, faced lawmakers today (Jan. 12) at his confirmation hearing.

Carson declined to commit to any real policy specifics, offering vague answers to most questions from politicians of either party while mouthing the right platitudes.

But one moment helped bring home the reality of putting someone with no experience leading a large financial organization in charge of HUD’s more than $40 billion budget, most of which is funneled to rental subsidies and housing investments around the country.

Senator Elizabeth Warren, a reliable critic of financial impropriety, began her time questioning Carson with a simple question: “Can you assure me that not a single taxpayer dollar that you give out will benefit the president-elect and his family?”

As any New York real estate developer worth his or her salt would know, HUD’s investments—particularly its urban renewal programs—have been corruptly turned to private gain in the past, particularly during the mid-20th century, when Robert Moses dominated urban planning in the city.

“I can assure you that the things that I do are driven by a sense of moral values,” Carson began. But Warren cut him off, noting the breadth of the department’s financial reach.

“My concern is whether, among the billions of dollars that you will be responsible for handing out, can you just assure us not one dollar will go to the benefit of the president-elect or his family?” Warren asked.

Answering the question with a thought experiment about $10 going to the Trump family, Carson ultimately concluded that he “will manage things to the benefit of the American people.”

Replied Warren: ”The problem is that you can’t assure us that HUD money, not of $10 varieties, but of multimillion-dollar varieties, won’t end up in the president-elect’s pockets. And the reason you can’t do that is that the president-elect is hiding his business interests from you, from me and the rest of America. The president-elect knows, and his family knows, what will benefit him, but the American people don’t.”

Warren is referring to the fact that, since Trump has not disclosed his tax returns, Americans have no idea what companies he may benefit from, particularly those hidden behind opaque corporate registrations.

Trump and his lawyers announced on Jan. 11 that the Trump organization’s assets will be managed by his two eldest sons. The organization will appoint its own ethics officer and refrain from doing deals with foreign parties or in foreign jurisdictions, but will otherwise remain as before. Ethics watchdogs from across the political spectrum, including Walter Shaub, the head of the US Office of Government Ethics, say these actions fail to eliminate the conflicts of interest faced by the president.

And the conflicts we know about, without needing a tax return from Trump, include operating a large real estate portfolio in cities that receive hundreds of millions of dollars in development funding and rental subsidies from the federal government.

“Nothing short of divestiture will resolve these conflicts,” Shaub concluded in remarks delivered yesterday (Jan. 11) at the Brookings Institution (pdf) .