This isn’t the petty Washington corruption of lobbying favors or excess campaign donations. It is far more unseemly and dangerous to democracy.

Kathleen Clark, a professor of ethics at Washington University in St. Louis, told NPR, “when Donald Trump is dealing with the Chinese government on behalf of the United States, he may also be thinking about what the Chinese government can do not just for the U.S. but for Donald Trump and his businesses and his own financial well-being.”

President Trump, his daughter and Mr. Kushner have all said that they have stepped away from their businesses. Ms. Trump has transferred her brand’s assets into a trust overseen by her brother-in-law, Josh Kushner, and sister-in-law, Ms. Meyer. These businesses carry on without them and bear their very powerful names. Meanwhile, the legal arrangements to keep them at arm’s length from those businesses remain opaque.

Various ethics lawyers charge that the Trumps are violating the Foreign Emoluments Clause of the Constitution, which forbids any “person holding any Office of Profit or Trust under the United States” from accepting “any present, Emolument, Office, or Title, of any kind whatever, from any King, Prince or foreign State” — unless Congress explicitly consents. Citizens for Responsibility and Ethics in Washington, a progressive government watchdog organization, has filed a lawsuit asserting that the president is receiving illegal payments from foreign governments through his companies.

In an interview with The Washington Post, Eric Trump said, “There are lines that we would never cross, and that’s mixing business with anything government.” The president himself, after pledging to “drain the swamp” during the campaign, has done little on the ethics front other than cancel ethics training for White House personnel and threaten to defang the Foreign Corrupt Practices Act.

The White House should remember the scandal that shook China only a few years ago. Former Prime Minister Wen Jiabao was disgraced after a New York Times report showed how his family members accumulated more than $2.7 billion, including large investments in precious stones. (His wife was known as “the Diamond Queen.”) Before Xi Jinping became president, Bloomberg News revealed that his relatives were worth more than $100 million.