(CNN) When Democrats take control of the House in early 2019, one of the first things they are likely to go after is President Donald Trump's tax returns.

Rep. Richard Neal, D-Massachusetts, who is expected to take over as the chairman of the House Ways and Means Committee, has already signaled that he plans to ask Trump to voluntarily hand over the returns (ha!) and, if the President doesn't comply, to formally request that the Treasury Department release Trump's returns to a small-ish group of lawmakers on Capitol Hill.

"I assume that there would be some sort of a court case, but we'd have to wait and see," Neal told The Washington Post earlier this month

In case you've forgotten: Trump is the first president in the modern era to refuse to release any of his tax returns. Prior to his election, he was the first major party presidential candidate not to release his returns. There is no law that demands that presidents release their returns, of course, but past presidents have done so out of a desire to be transparent with the voting public about their financial status and ties.

Trump has repeatedly rejected the idea that he release any of his returns, insisting that there's nothing in them that is particularly revelatory and noting that his taxes are under audit and, therefore, it's inadvisable for him to release them. He trotted out those same lines during his post-election news conference last Wednesday.

Here's his full answer on his returns:

"Well, look, as I've told you, they're under audit. They have been for a long time. They're extremely complex. People wouldn't understand them.

"They're done by -- among the biggest and best law firms in the country. Same thing with the accounting firms, the accountants are a very, very large, powerful firm from the standpoint of respect. They're highly respected, big firm. A -- a great law firm, or you would -- you know it very well. They do these things. They put them in.

"But people don't understand tax returns. Now, I did do a filing of over a hundred pages, I believe, which is in the offices. And when people went and saw that filing and they saw the magnitude of it, they were very disappointed.

"And they saw the -- you know, the detail. You get far more from that. And I guess we filed that, now, three times. But you get far more from that than you could ever get from a tax return.

"But when you're under audit -- and I'm on a very continuous audit because there are so many companies -- and it is a very big company, far bigger than you would even understand. But it's a -- it's a great company.

"But it's big, and it's complex and it's probably feet-high. It's a very complex instrument. And I think that people wouldn't understand it.

"But if I were finished with the audit, I would have an open mind to it. I would say that. But I don't want to do it during the audit.

"And -- and really no lawyer -- even from the other side they say, often, not always -- but when you're under audit, you don't have -- you don't subject it to that. You get it done, and then you release it.

"So when that happens, if that happens, I would certainly have an open mind to it."

Riiiiiiiiiight.

So, the reason Trump isn't releasing his returns is because a) he's under "a very continuous audit because there are so many companies" and b) "They're extremely complex. People wouldn't understand them."

Which, like ... what?

The truth of this is that Trump's explanations -- if that's what we're calling them -- are sort of secondary here.

The real issue here is a 1924 provision in the Internal Revenue Service tax code that allows the chair of the House Ways and Means Committee and the chair of the Senate Finance Committee can ask for anyone's tax returns -- including the president's! -- from the Internal Revenue Service -- as long as they can demonstrate that the returns are necessary for an ongoing investigation.

That clause, according to this great piece by CNN's Jeanne Sahadi , could well lead to the eventual public disclosure of Trump's returns:

"The chairmen of the tax-writing committees -- whether they act together or alone -- don't need to disclose that they've requested the president's returns. But they may choose to -- and likely would -- share the returns with their committee members in closed session.

"If the committee thinks releasing the returns to the House or Senate would further a legitimate committee purpose, they're permitted to do so, according to George Yin, a former chief of staff at the Joint Committee on Taxation and a professor of law at the University of Virginia.

"At that point it's up to the full chamber to decide whether to make the returns public. 'Of course, as a practical matter, it's a little hard to imagine information going to the full House or Senate and not becoming public,' Yin said."

Given that potential sequence of events, you can see why Trump -- who has been adamant in his refusal to release his returns -- would move to block the Treasury Department/IRS from releasing any of his returns to Neal. The legal challenge from the White House would likely center on whether or not Neal is conducting a legitimate investigation in which the returns are a critical piece or whether it's simply part of a broader Democratic effort to embarrass Trump in advance of the 2020 election.

What seems certain now: House Democrats will make a move to see Trump's taxes. Trump, who, I believe, thinks the release of the returns could do him real political harm, will fight like hell to keep them from doing so.

Who wins? No clue. But there's no question that we are closer to seeing Trump's tax returns today than we have been at any point since he began to run for president in 2015.