Honestly, I think we're going to have to accept that Trump is a billionaire. A fraud, sure, but proving someone with $billions in assets and $billions in debt is not a billionaire will depend entirely on valuation procedures that are not understandable to non-specialists.
There's a ton of real estate and business assets that can have their values take wide ranges.
I think the key here is going to be
why Trump is a billionaire.
For example, we already know that the Trump family transferred hundreds of millions of dollars to Donald before he was an adult, through fraudulent business activity. For example, Fred made 10 year old Donald the CEO of a cleaning services company that maintained the family's apartment buildings in Queens, and then had the company overcharge the Trump family business for supplies. Donald pocketed the surplus "profits" but the reality was this was just way for Fred to make kiddie Donald rich without paying the correct amount of taxes.
We also know that adult Donald's real estate empire was severely mismanaged, several times resulting in bankruptcy and several more times only saved from bankruptcy by enormous infusions of foreign cash, including from organized crime and from Russian oligarch and from Russian oligarchs involved in organized crime. Donald owes the longevity of his business empire to the Russians (and people from other former Soviet republics). Eric and Don Jr. have talked about their gratitude for the Russians publicly on numerous occasions, before Donald ran for president. For example, in 2008 Don Jr said "Russians make up a pretty disproportionate cross-section of a lot of our assets" and in 2016 Eric said "We don’t rely on American banks. We have all the funding we need out of Russia." Trump's tax returns are likely to show a long history of servicing his Russian debts, as tax deductions.
Then there's the fraudulent way Trump has inflated his self worth, once jumping roughly $4billion in a single year when his accountants decided to include the hypothetically monetized value of the Trump brand name, by converting his recently received licensing fees into a lump sum using the treasury rate. So if someone paid him $1 million in licensing fees for a hotel in a year when the treasury rate dropped to 0.25%, he claimed that his brand name was worth $200k/0.25 pecent, or $400,000,000. Even if the entire hotel was only worth half that, he claimed his personal net worth increase from that deal went up by a multiple of his licensing fee. His entire business history is full of this of this kind of tomfoolery, attempts to make himself appear richer than he is. His tax returns will reveal all kinds of deals like this, not to mention the litany of real estate deductions he's using to show "losses" on profitable properties.
Trump's tax returns will also show that he is still receiving net income from his ownership stake in a variety of businesses and properties. Let's not forget that he refused to put his assets into a blind trust, the way every previous president with assets has done. He's still personally making money every time he invites the Saudi royal family to stay in his DC hotel.
I mean realistically, we can see what Trump owns because he likes to put his name on things that he owns. He owns 17 gold courses that collectively make over $200m per year. He has partial or full ownership stakes in approximately 60 different buildings, mostly hotels/apartments/commercial spaces. Then there's a private jet subcontractor, a variety of real estate-related development corps, and a media company. All of this stuff is public knowledge. It's not always straightforward to value a company or a property, but individually I agree that they add up to more than a billion dollars by any commonly used metric. So it's fair to call him a billionaire, I think.
But actually seeing the annual paperwork sure would make this whole discussion a lot easier. If the American President has committed tax fraud, don't the American people deserve to know? How can we be expected to pay our fair share if he won't?