(CNN) President Donald Trump , by his simultaneous existence as a real estate tycoon and President, continues to test the US Constitution in ways that the founding fathers didn't anticipate and for which the current legal and political systems are completely unprepared.

The founders didn't specifically anticipate a hotelier President pushing his golf resort as the ideal location for an international meeting of heads of state

They didn't specifically say an Air Force crew couldn't use taxpayer dollars to stay at a resort owned by the President in a foreign country , which may or may not be suffering as a result of his presidency.

They didn't anticipate the Air Force more generally starting to send more flights in need of refueling to the financially troubled airport closest to that resort , eschewing military bases that might provide cheaper fuel, as Politico reported

They didn't anticipate the President's subordinates would begin serially staying at his properties or planning parties at them, potentially currying favor with their boss.

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And they didn't anticipate a President who would be so willing to push every rule to the breaking point -- or be so cavalier about the appearance of self-dealing.

But the real problem is that Congress hasn't, either. There's nothing on the books curtailing any of this -- which means that the President could be in violation of the Constitution without breaking the law.

Emoluments rise again

All we really have when it comes to presidential self-dealing is a ban on what the Constitution calls emoluments -- those are titles or gifts from foreign or domestic governments beyond the salary all Presidents are paid.

"I got sued on a thing called emoluments," Trump said last month, referencing four lawsuits challenging his financial entanglements in office. "Emoluments. You ever hear the word? Nobody ever heard of it before."

He later offered his own definition.

"What it is, is presidential harassment because this thing is costing me a fortune, and I love it, OK? I love it because I'm making the lives of other people much, much better."

He's generally right that while constitutional scholars might have always known about emoluments, everyone else has been having to get up to speed, including the Congressional Research Service , which recently published a primer on the three times emoluments are mentioned in the Constitution.

Between the Foreign Emoluments Clause, the Domestic Emoluments Clause and The Ineligibility Clause, the issue takes up a lot of space in the Constitution, especially considering they cover an issue that, according to CRS, has never been litigated in a major way in court.

Here are those clauses:

The Foreign Emoluments Clause; Article 1, Section 9:

"[N]o 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."

The Domestic Emoluments Clause; Article 2, Section 1:

The President shall, at stated Times, receive for his Services, a Compensation which shall neither be encreased nor diminished during the Period for which he shall have been elected, and he shall not receive within that Period any other Emolument from the United States, or any of them."

The Ineligibility Clause; Article 1, Section 6:

"No Senator or Representative shall, during the Time for which he was elected, be appointed to any civil Office under the Authority of the United States, which shall have been created, or the Emoluments whereof shall have been encreased during such time; and no Person holding any

Office under the United States, shall be a Member of either House during his Continuance in Office."

Trump's concern for his bottom line

Trump has argued recently that he's rich enough that he doesn't need help from foreign governments, Mike Pence or the Air Force. He said Monday he would release a new review of his wealth before Election Day, although he may have been referring to personal financial disclosures like those he has filed each year since 2015.

Trump is indisputably wealthy, although the exact size remains a mystery. He likes to complain that his time as President will cost him, as he did during a speech in Pennsylvania in August . This is evidence, if nothing else, that he's concerned about his bottom line during his time in the Oval Office.

"This thing is costing me a fortune, being President," he said, adding a reference to foreigners staying at his hotel near the White House in Washington.

"Somebody said, "Oh, he might have rented a room for — to a man from Saudi Arabia for $500." What about the $5 billion that I'll lose? You know, it's probably going to cost me — including upside, downside, lawyers — because every day, they sue me for something. These are the most litigious people. It's probably costing me from $3 to $5 billion for the privilege of being — and I couldn't care less. I don't care," he said.

The exact amount that being President might cost Trump is probably nowhere near that figure since Forbes recently guessed his total wealth at $3.1 billion. Trump takes what Forbes says very seriously, according to his former lawyer Michael Cohen, who alleged Trump would inflate his wealth to appear higher on the magazine's ranking of billionaires. Forbes, for what it's worth, agrees with Trump that he's lost money since becoming President

Taxpayer money in Trump's pockets

Harvard constitutional law professor Laurence Tribe, who thinks Trump should be impeached, tried to give Trump a lesson Twitter about emoluments recently.

Memo to POTUS: There are TWO Emoluments Clauses. The one you're violating when you line your pocket by having Pence stay at your resort & commute is the Domestic EC. The one you're planning to violate by having the G7 stay at the Doral w/out Congress's consent is the Foreign EC. — Laurence Tribe (@tribelaw) September 3, 2019

"Memo to POTUS: There are TWO Emoluments Clauses. The one you're violating when you line your pocket by having Pence stay at your resort & commute is the Domestic EC. The one you're planning to violate by having the G7 stay at the Doral w/out Congress's consent is the Foreign EC."

But that tweet was sent before the latest development that the Air Force is investigation how and why an Air Force crew stayed at Trump's Turnberry resort in Scotland on a refueling mission.

"Use by Air Force officials of Trump properties presents a potential emoluments problem, much like Pence's stay at the Trump resort, because both cause federal government money to wind up in Trump's pocket," said the CNN legal analyst Elie Honig. "An emoluments violation is not a crime in and of itself, but it certainly could provide a basis for impeachment or civil remedies."

Another Trump antagonist, Walter Shaub, who is a former Director of the Office of Government Ethics, laid out why the Air Force development is, at the very least, not a good look.

"To believe USAF's claim that stays at Turnberry were normal, you'd have to believe: its a coincidence Trump owns it, emoluments are ok, no hotels under $166 were within 30 miles of the airport, the cost of meals + incidentals is irrelevant and an appearance of corruption is fine."

To believe USAF's claim that stays at Turnberry were normal, you'd have to believe: its a coincidence Trump owns it, emoluments are ok, no hotels under $166 were within 30 miles of the airport, the cost of meals + incidentals is irrelevant and an appearance of corruption is fine. — Walter Shaub (@waltshaub) September 8, 2019

What to do about an emolument violation

Trump has been the subject of four different Emoluments lawsuits and they are in various stages of review. A key issue they've encountered is standing and whether those bringing them, ranging from states and public interest groups to members of Congress, have suffered a legal wrong sufficient to bring the lawsuit. That CRS report offers a good roundup of where each lawsuit stands.

But given that these are untried constitutional questions, the more appropriate venue to consider violations of the Emoluments clauses would be in impeachment proceedings. Democrats on the House Judiciary Committee are expected this week to vote on formal parameters for their impeachment investigation and which is expected to focus on Trump's potential obstruction of justice with regard to the Russia investigation, hush money payoffs he is alleged to have masterminded in 2016 to women alleging affairs with him, and the possible offer of pardons to people facing legal trouble in his orbit. What's not yet clear is whether possible Emoluments violations will be added to the list.

A presidency stressing the government

Part of the reason for this new and unprecedented legal tension is that Trump did not divest himself from his holdings when he took office, but rather placed his business in a trust run by his children and to which he has access.

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"It's yet another example of some rarely invoked provision of the law or the Constitution and because Donald Trump is willing to push limits like no President before him, we're seeing all of these novel legal issues raised," said Honig.

Most of those issues have to do with some way that Trump and his administration are trying to test a set of laws passed with a different intent.

This is, after all, the administration that declared a national emergency to divert Pentagon funds to build a border wall Congress doesn't want. It's the administration that wants to completely reinterpret 140 years of immigration law to kick more people out of the country. Trump cited a 1977 law focusing on drug traffickers and terrorists to threaten to completely cut off economic activity from China

In the case of emoluments, he's testing constitutional text Congress never before had a reason to address in the first place.