Didn’t people see that big stack of papers at his press conference? Photo: Andrew Harrer/Bloomberg via Getty Images

Questions about how to interpret the Emoluments Clause, an obscure provision in the Constitution, surged after Donald Trump was elected president. On Monday, a watchdog group plans to file a lawsuit against Trump in Manhattan federal court alleging that he’s violating the clause, so we may finally find out if it’s unconstitutional for the president’s businesses to accept payments from foreign governments.

The Emoluments Clause states that “no Person holding any Office of Profit or Trust under [the United States], shall, without the Consent of the Congress, accept of any present, Emolument, Office, or Title, of any kind whatever, from any King, Prince, or foreign State.” Citizens for Responsibility and Ethics in Washington argues that this applies to rent, room rentals, and other fees at Trump properties. According to the New York Times, the suit will not seek monetary damages, but will ask the court to order Trump to stop taking such payments from foreign governments.

Politico reports that the suit will focus on Trump Tower leases held by the Industrial and Commercial Bank of China, a state-run bank, and the Abu Dhabi Tourism and Culture Authority, which is part of the United Arab Emirates government.

At his press conference earlier this month, Sheri Dillon, Trump’s lawyer, argued that the Emoluments Clause does not apply if the foreign entity is paying the fair-market value, like the standard hotel-room fee. “No one would have thought when the Constitution was written that paying your hotel bill was an emolument,” Dillon said.

Eric Trump, who will run his father’s business with his brother during Donald Trump’s presidency, told the Times that the Trump Organization has gone beyond what’s required by law by promising to donate profits collected from foreign governments to the U.S. Treasury. “This is purely harassment for political gain, and, frankly, I find it very, very sad,” he said of the lawsuit.

A copy of the legal complaint provided to the Washington Post counters that the clause “is no relic of a bygone era, but rather an expression of insight into the nature of the human condition and the preconditions of self-governance. And applied to Donald J. Trump’s diverse dealings, the text and purpose of the Foreign Emoluments Clause speak as one: this cannot be allowed.”

The group filing the suit includes Harvard constitutional scholar Laurence Tribe, Obama administration ethics lawyer Norman Eisen, George W. Bush administration ethics counsel Richard Painter, and Fordham University law professor Zephyr Teachout, among others.

One question that could derail the case before it gets started is whether the ethics watchdog has standing to sue. The plaintiffs plan to argue that Trump has caused them specific harm because his vast business conflicts are a distraction from their primary mission as an ethics organization.

“CREW’s whole purpose is about combating corruption in the federal government,” Painter told the Post. “So up until this point, the two major causes of corruption in the government were the revolving door in Washington and campaign finance. The vast majority of resources were spent on that. It was a two-front war, and now this opens up a third front.”

Even if the suit isn’t successful, it could shed more light on the president’s business dealings. Eisen said they hope the suit will allow them to obtain a copy of Trump’s tax returns, which could reveal which countries he does business with, and the money he may owe them — with no leaking required.