"Despite its mandatory obligation, the Treasury Department failed to comply with the law and denied the Committee's request," said House Ways and Means Committee Chairman Richard Neal, D-Mass., in announcing the move. "The Administration also refused to comply with the subpoenas I subsequently issued in an effort to obtain the materials. Due to that noncompliance, the Committee is now pursuing this matter in the federal courts."

The decision to sue comes a full three months after Neal first requested Trump's tax returns from Treasury Secretary Steve Mnuchin, citing an IRS statute that states that the treasury secretary "shall" turn over the tax return of any American if the chair of the House Ways and Means Committee requests it. In his initial request, Neil asked for personal tax returns from 2013 to 2018 as well as returns for eight business entities affiliated with Trump.

Mnuchin denied that request, insisting that Neal didn't have any credible reason to ask for Trump's returns -- other than to score political points. And that decision led us to today.

In truth, everything from April 3 (when Neal first requested Trump's returns) until today has been predictable prelude.

There is -- and was -- a 0% chance that Trump (or his proxy Mnuchin) was ever going to voluntarily turn over the President's tax returns. Why? Because, at some point in the relatively early days of the 2016 campaign, Trump and his advisers made the decision that whatever was in his returns would be far more damaging to his chances of being president than the bad press he would get by not releasing them. (Trump is the first major-party presidential nominee to release no tax returns and the first US president since Watergate to refuse to release any returns.)

That initial decision has been justified in all sorts of different ways by Trump and his top aides.

The longest-running excuse -- er -- explanation is that Trump is currently under audit and that you don't release your returns while under audit.

"You don't learn anything from a tax return," Trump said at a GOP debate in February 2016. "I will say this. Mitt Romney looked like a fool when he delayed and delayed and delayed and Harry Reid baited him and Mitt Romney didn't file until a month and a half before the election and it cost him bigly. ... As far as my return, I want to file it except for many years, I've been audited every year. Twelve years or something like that. Every year they audit me, audit me, audit me. ... I will absolutely give my return but I'm being audited now for two or three [years' worth] now so I can't."

He's repeated that same basic line for years now -- although it's not, strictly speaking, accurate. There is no law that bars Trump from releasing his returns. In fact, there is precedent for a president -- say that 10 times fast! -- to do so. Seeking to knock down the idea that he was a crook, Richard Nixon released his tax returns , while in office, in 1973. So it's not that Trump can't release his returns under audit. It's that he doesn't want to.

The other main reason offered by Trump's allies for his refusal to turn over his returns is that no one cares to see them. The most outspoken advocate of this position is White House counselor Kellyanne Conway. "We litigated this all through the election. People didn't care," she said way back in early 2017 . "They voted for him, and let me make this very clear: Most Americans are very focused on what their tax returns will look like while President Trump is in office, not what his look like."

That is, also, not strictly accurate. There's no way of Conway knowing whether people voting for Trump did so knowing (and not caring) that he hadn't released his tax returns because there was no question on the 2016 exit poll that remotely dealt with that issue. And subsequent polling suggests the opposite is true: In a late April CNN-SSRS national poll, 66% of respondents said Trump should release his taxes publicly, while 32% said he should not.

The point here is that -- whatever the reason Trump and his supporters offered in the moment -- this was always the endgame. Refuse to cooperate at all turns. Force the issue into the courts. Hope for a favorable ruling but, short of that, root for a drawn-out process whereby any sort of ruling isn't offered until either a) Trump has already secured a second term or b) Trump has lost reelection and the state of his tax returns is no longer of such interest.

We've been heading in this direction for the past four years. Now the real fight -- the legal one -- begins. Trump hopes it won't end anytime soon.