Richard Neal may well be right, but it won’t be as easy as he might think. The House Ways and Means chair told reporters yesterday that he would sue to force Treasury Secretary Steve Mnuchin to comply with his demand to surrender Donald Trump’s tax returns. “We think the law is unambiguous,” Neal declared in predicting victory:

House Ways and Means Chairman Richard Neal indicated Tuesday that Democrats would go straight to federal court to try to force the administration to give up President Donald Trump’s tax returns, skipping a subpoena or a contempt vote.

“There doesn’t have to be any intermediary step. They seem not to be paying a lot of attention to the subpoenas, so take it from there,” Neal (D-Mass.) told reporters, adding that he’d have a response by the end of this week to the rejection of his request for the returns. …

Neal, in his fullest comments since Mnuchin’s decision, said: “That’s what a federal judge will decide. We think the law is unambiguous.”

The statute certainly reads unambiguously. The law, on the other hand — including the precedents set by the courts — might be somewhat less so. Donald Trump’s attorney raised that issue with the Department of Justice after Mnuchin sought legal guidance on the merits of Neal’s request under 26 USC 6103(f). William Consovoy brought up a landmark Supreme Court decision from the McCarthy era that curtailed Congress’ investigative reach, an argument that helped convince Mnuchin and the DoJ to stand firm on their denial.

In my column for The Week, I argue that Earl Warren’s ruling in Watkins v US appears to speak to this particular fight, if not the other major legal war brewing between the White House and Congress:

In a letter last month to the Treasury Department’s general counsel, Trump’s personal attorney, William Consovoy, pointed to the Supreme Court’s decision in Watkins v. US, a 1957 case brought against the House Un-American Activities Committee during the “Red Scare.” Labor organizer John Watkins was cited for contempt of Congress for refusing to provide information not pertinent to a legitimate investigative purpose. Watkins sued and eventually the Supreme Court ruled 6-1 in his favor, a ruling hailed at the time as a major limitation on Congress’ reckless use of its investigative authority.

Former Chief Justice Earl Warren’s opinion from that time speaks to some of the issues in contention in the current fight. “Congress has no general authority to expose the private affairs of individuals,” Warren concluded, “without justification in terms of the functions of Congress.” He specifically cited a need to demonstrate a “legislative purpose,” noting that “[i]t cannot simply be assumed that every congressional investigation is justified by a public need that overbalances any private rights affected.” …

Watkins makes it clear that one party winning a majority in either chamber of Congress does not authorize fishing expeditions through the private affairs of any American, whether president or pipefitter. Without an explicit and clear predicate for Congress to review Trump’s tax returns, the courts may well side with Warren in this instance. Otherwise, both parties could misuse confidential tax information to declare open season on their political opponents, the allies of their political opponents, their critics, and so on.

This argument isn’t a silver bullet for Trump and Mnuchin. In Watkins, Warren wrote that HUAC lacked any predicate for demanding testimony on private political opinions and positions. “The resolution of authorizing the Un-American Activities Committee does not satisfy this requirement,” Warren wrote, especially in light of the abuses it committed in practice. “Protected freedoms should not be placed in danger in the absence of a clear determination by the House or Senate that a particular inquiry is justified by specific legislative need.”

However, Ways and Means is a standing committee with fairly broad legislative authority on taxation. Its mission includes ensuring fair and legal practices within any administration, which is why the clause exists in Section 6103. Part of Neal’s argument to Watkins is already apparent.

The question for the court, however, will be whether Neal is demanding those records not just in consonance with the mission of Ways and Means but also for a specific “function[] of Congress.” As Watkins made clear, just claiming authority for “oversight” isn’t going to cut it. That seems especially true when the activity being overseen is private activity with no connection to the function of government, and therefore no connection to a legitimate function of Congress. If Neal has evidence of a crime, that might change the calculation, but that would prompt questions as to whether Congress might be usurping a prosecutorial or judicial role in private affairs, too.

If Neal can tie this demand to some legitimate legislative concern and not just “oversight,” a court might presumptively rule in his favor given the language of the statute. The courts might well take into account the hyperpartisan nature of this Congress and treat Neal’s claim with enough skepticism that he will have to answer some tough questions about his real purposes in pushing for Trump’s returns. Neal might have to answer for his own reluctance to reveal his tax returns, too:

The House Democrat demanding President Trump’s tax returns is coming under fire for not releasing his returns and spending lavishly on lobbyists and potential donors.

Massachusetts Rep. Richard Neal, chairman of the House Ways and Means Committee, hasn’t released his recent returns, though said he planned to in the future. …

Back home, he was criticized for demanding Trump’s returns but not releasing his. Mass Live reported: “Neal has been drawing charges of hypocrisy for not releasing his own taxes. Although he said Thursday that he likely would release them, he did not give a date.”

And yesterday, a guest column in the Boston Globe looked through his recent Federal Election Commission report and found that the congressman spent an amount close to the $500,000 he raised for his reelection in just three months on fancy dinners and entertainment.

Sauce for the goose living in glass houses and throwing stones, and all that.