Richard Painter, a professor of law at the University of Minnesota, was the chief White House ethics lawyer for President George W. Bush from 2005 to 2007. Norman Eisen, a visiting fellow at the Brookings Institution, was the chief White House ethics lawyer for President Obama from 2009 to 2011.

As government ethics lawyers who have, respectively, counseled the most recent Republican president and the most recent Democratic one, we have watched Donald Trump’s campaign with increasing concern. We have come to believe a Trump presidency would be ethically compromised for the following reasons:

Democratic vice presidential nominee Sen. Tim Kaine said on Sept. 14 that he's concerned about Donald Trump's overseas business interests, especially in Russia. (Peter Stevenson/The Washington Post)

Opacity. Trump’s refusal to disclose his tax returns shields critical information about his finances that is not found in the basic details he is required to provide on his candidate financial disclosure. For example, his disclosure form does not cover his tax deductions and exemptions and any loopholes he takes advantage of; each represents a policy issue on which he has a potential conflict. To take another example, how much tax is Trump paying or sheltering domestically vs. in foreign jurisdictions? That needs to be known to ascertain which nations Trump has financial ties to and where he may be susceptible to pressure. Absent this information, it is impossible to assess the potential conflicts a President Trump would face in making decisions.

Lack of divestment. Trump has said that if elected he would have his children manage his business and would not discuss business matters with them. That is not sufficient. Presidents for the past half-century have either converted assets to simple, conflict-free holdings such as U.S. government bonds, adopted blind trusts or done both. Blind trusts were used by Presidents Reagan, Carter, both Bushes and Bill Clinton, none of whom had holdings comparable to the size and complexity of the Trump empire. A true blind trust means that your holdings are liquidated and placed in new investments unknown to you by an independent trustee who manages them free of familial or other bias. Trump has so far declined to commit to taking those steps, and doing so would not be easy for him even if he agreed. A large number of Trump businesses are branded with his name as an integral part of their value. Even if ownership were placed in trust, Trump and everyone else would remain well aware of these assets. Assumption of the presidency requires a much more definitive break than Trump has, so far, been willing to make.

Domestic conflicts. Without considerable additional detail about Trump’s finances, we cannot be sure his decisions on domestic matters would be conflict-free. When Trump nominated his Cabinet, offered his budget and invited people to White House meetings, would he be choosing with an eye toward his or his family’s business interests? Moreover, based on what we do know, there is ample cause for concern about conflicts. Take the example of bank regulation. Trump’s real-estate holdings appear to be heavily leveraged. That means that his businesses, like those of many in the real-estate field, are beholden to banks. It is not fanciful to question whether that would affect the Trump administration’s attitude toward regulation of banks and other lenders.

Foreign conflicts. Even more serious are the questions raised by Trump investments abroad. Those relate to some of the United States’ most important — and most sensitive — relationships, among them ones with Russia, China, India, South Korea and Turkey. When the United States must support or confront those nations, or their adversaries, would Trump act to benefit the national interest, or his and his family’s investments? Moreover, who are the foreign individuals with whom he has had financial ties, and how would those relationships affect his decisions? As the electorate considers those questions, it is entitled to more information.

Legal exposure. Because of Trump’s seeming unwillingness to set up a true blind trust, and the difficulty of his doing so, his potential foreign conflicts could raise immediate legal issues. Most federal ethics rules, surprisingly, do not apply to the president. But Trump would be covered by bribery laws and the Constitution’s emoluments clause, which broadly prohibits the president from accepting gifts “from any King, Prince, or foreign State.” The emoluments clause has been interpreted by the Justice Department to include any payment from a foreign government, except with the consent of Congress. Every time there was a financial transaction between a foreign government — or a company controlled by a foreign government — and any Trump entity, there would be a potential for favorable treatment that could violate this limitation, as well as the anti-bribery laws. That, too, gives us pause.

Veracity. Finally, we must address Trump’s propensity for dishonesty. It is disturbing that just 15 percent of his statements checked by PolitiFact are “true” or “mostly true.” No ethics program can work if the client is not honest.

To be sure, counsel for a President Hillary Clinton would have to address actual or apparent conflicts posed by the Clinton Foundation, but those have been disclosed and publicly vetted. They are nowhere near as obscure, profound and dangerous as Trump’s. The ethics lawyer who would have President Trump as his or her client would face a far more daunting task than either of us — or any of our colleagues in recent years — has ever confronted.