Every presidential nominee from a major party in the last forty years has released their tax returns to the public. Except Donald Trump.
The unprecedented nature of the Trump's business interests and lack of transparency has set off a years-long battle over his finances.
Now it's coming to a head. The Democratic controlled House Ways and Means Committee has subpoenaed the Treasury Secretary and IRS Commissioner to hand over six years of Trump's personal and business tax returns.
Chairman Richard Neal says he wants to review "the extent to which the IRS audits and enforces the federal tax laws against a sitting president."
This could end up going all the way to the Supreme Court.
Watch the video above to see how Trump has shielded his tax returns over the years as Democrats, the media and ethics officials clamor for them.