Donald Trump has flip-flopped on policy positions and performed about-turns in his political views. But the former real-estate mogul has remained steadfast in one matter: his refusal to release his tax returns.
Mr Trump based his presidential bid on his talents as a businessman, without revealing the details of his financial affairs. So the question of what is in Mr Trump's tax returns - and why he won't publish them - has simmered on.
Last night Rachel Maddow on her MSNBC show published details from two pages of Mr Trump's 2005 tax return.
So what can we learn from these documents?
1. Trump paid $38m (£31m) in tax on more than $150m (£123m) income
The figures show that Mr Trump paid an effective tax rate of 25 per cent on earned income.
Data from the Congressional Joint Committee on Taxation shows that this rate is well above the roughly 10 per cent the average American tax payer pays each year. But below the 27.4 per cent that taxpayers earning more than one million dollars a year average were paying at the time.
Mr Trump has previously boasted that he pays as little tax as possible. The White House said in a statement yesterday that he was "one of the most successful businessmen in the world, with a responsibility to his company, his family and his employees to pay no more tax than legally required".
In addition to the federal income taxes in 2005, the statement said, he paid “tens of millions of dollars in other taxes, such as sales and excise taxes and employment taxes, and this illegally published return proves just that.”
2. But he wrote off more than $100 million in business losses
Writing off this sum allowed him to save millions of dollars in tax payments he would otherwise have owed.
It's unclear what the source of these losses was. The White House described the losses as “large-scale depreciation for construction,” but did not elaborate.
During the election campaign the New York Times obtained a portion of Mr Trump's 1995 tax return, which showed he had lost almost one billion dollars.
The news outlet reported that the fallout from this financial wreckage allowed him to cancel out taxable income for an 18-year period. It's not clear if the losses reported in 2005 are part of this write-off.
3. Did Donald Trump or his allies leak the return?
For all the hype, the released portion of the 2005 tax return is not particularly damaging to Mr Trump. Some have even suggested that this helps him.
It has been previously suggested that the reason Mr Trump has refused to reveal his returns is that he has barely paid any tax and that he is faking the extent of his wealth.
Donald Trump Junior, the president's son responded to the leak by tweeting:
Soon social media sites were filled with speculation: Could Mr Trump had leaked his own return?
The theory was further fuelled by David Cay Johnston, a Pulitzer Prize-winning journalist and tax expert who obtained the documents. He said they had landed, unsolicited, into his email inbox.
“It’s entirely possible that Donald sent this to me,” Mr Johnston told Ms Maddow on her show. “It’s a possibility, and it could have been leaked by someone in his direction.”
Others noted that the tax return was labeled “client copy,” ostensibly indicating that it came from someone close to him, rather than the Inland Revenue Service.
4. He paid millions in tax due to a law he is now trying to scrap
Mr Trump and his wife, Melania, paid only $5.3 million under regular federal income tax guidance - a tiny sum for someone of his reported wealth.
The bulk of the taxes paid in 2005 came instead from what's known as the "alternative minimum tax", a law aimed at preventing high-income earners from paying minimal taxes.
Under this law he paid out a further $31 million, bringing his tax rate to 25 per cent of earnings.
Critics say the tax has ensnared more middle-class people than intended, raising what they owe the federal government each year.
And Mr Trump during his campaign called to abolish the alternative minimum tax and provide the lowest overall tax rate since World War Two.
5. The returns leave key questions unanswered
These two pages fail to address the biggest questions surrounding Mr Trump's financial affairs.
The first weeks of Mr Trump's presidency have been plagued by allegations of financial ties between Mr Trump or top allies in his campaign and the Kremlin.
Some of the president's businesses have also been named in connection with members of the Russian mob in New York and Florida.
These documents do not provide information on the sources of his income or the nature of his investments.
The mystery continues.