“Offensive operations,” George Washington once wrote, “often times is the surest, if not the only (in some cases) means of defence.” Count this among the few times that Donald Trump can claim similarity with the first president. In hoping to forestall Democratic fishing expeditions into his private finances, Trump sued Congress today to block executions of subpoenas issued to his accountants:

President Trump and his business sued House Oversight Committee Chairman Elijah E. Cummings (D-Md.) in a bid to block a congressional subpoena of his financial records on Monday.

The lawsuit seeks a court order to prevent Trump’s accounting firm from complying with what his lawyers say is an improper use of subpoena power by congressional Democrats.

That might be a tough argument for the courts to parse out. Congress has wide-ranging subpoena power, but as the Congressional Research Service noted almost two years ago, subpoenas have to serve a legitimate legislative purpose. Oversight of the executive branch is one of those legitimate purposes, but Trump’s attorneys argue that the subpoenas from Cummings and House Oversight don’t have that basis — because they’re investigating private behavior rather than official conduct:

In the complaint filed Monday, Trump’s lawyers argue that the subpoena of Mazars “lacks a legitimate legislative purpose” and is seeking information about Trump as a private citizen, before he took office.

“With this subpoena, the Oversight Committee is instead assuming the powers of the Department of Justice, investigating (dubious and partisan) allegations of illegal conduct by private individuals outside of government,” it says. “Its goal is to expose Plaintiffs’ private financial information for the sake of exposure, with the hope that it will turn up something that Democrats can use as a political tool against the President now and in the 2020 election.”

The complaint seeks a permanent injunction to prevent Cummings from taking any actions to enforce the subpoena, and a temporary restraining order and preliminary injunction prohibiting Mazars from producing the requested information.

Is the distinction that clear, though? CRS addressed this question almost right off the bat in its analysis:

A committee’s investigation must have a legislative purpose or be conducted pursuant to some other constitutional power of the Congress, such as the authority of each House to discipline its own Members, judge the returns of the their elections, and to conduct impeachment proceedings.460 Although the early case of Kilbourn v. Thompson461 held that the investigation in that case was an improper probe into the private affairs of individuals, the courts today generally will presume that there is a legislative purpose for an investigation, and the House or Senate rule or resolution authorizing the investigation does not have to specifically state the committee’s legislative purpose.462 In In re Chapman, 463 the Court upheld the validity of a resolution authorizing an inquiry into charges of corruption against certain Senators despite the fact that it was silent as to what might be done when the investigation was completed.

Even so, it’s not an “unlimited” power:

Despite the Court’s broad interpretation of legislative purpose, Congress’s authority is not unlimited. Courts have held that a committee lacks legislative purpose if it appears to be conducting a legislative trial rather than an investigation to assist in performing its legislative function.476 Furthermore, although “there is no congressional power to expose for the sake of exposure,”477 “so long as Congress acts in pursuance of its constitutional power, the Judiciary lacks authority to intervene on the basis of the motives which spurred the exercise of that power.”

This looks more like a legislative trial, as Cummings has no real predicate for legislative action on the basis of Trump’s finances. This isn’t as cut-and-dried as the authority of the Ways and Means chair to call up tax returns for IRS oversight purposes. Cummings will have to show a legitimate “legislative purpose” for sticking his nose into Trump’s business records. Chapman dealt with official misconduct in the Senate for which the legislature had direct responsibility. A court might not look favorably on these very different circumstances, but we’ll soon see.

So with all this going on, will Treasury cough up Trump’s tax returns by the deadline tomorrow? It’s tough to choose between the two possible answers here, which are no and … hell no. To be fair, CNN’s Lauren Fox reaches the same conclusion, but CNN apparently sees the need for some kind of narrative tension after the Muellermas letdown:

The IRS has until tomorrow to turn over six years of President Trump’s personal and business tax returns. @FoxReports explains from Capitol Hill: pic.twitter.com/xrhtuh4Ay7

— CNN (@CNN) April 22, 2019

The Hill also does some chin-stroking over tomorrow’s deadline, and the inevitable court fight that will follow:

The Trump administration this week is expected to miss a second deadline for providing President Trump’s tax returns, making it all but certain that a legal fight will ensue.

House Ways and Means Committee Chairman Richard Neal (D-Mass.) gave the IRS until Tuesday at 5 p.m. to turn over six years of Trump’s tax filings, and said he’d consider a failure to comply to be a denial of the request. Neal initially set a deadline of April 10 in an April 3 letter to the IRS, but the administration missed that deadline.

Some Democrats say their next move will likely involve issuing a subpoena for the documents. Administration officials have said the president will not turn over his returns, meaning a subpoena standoff would shift the battleground into the courts.

“If the IRS does not comply with the request, Chairman Neal would likely issue a subpoena for the returns and return information as detailed in the initial letter,” Rep. Judy Chu (D-Calif.), a Ways and Means Committee member, said last week on a call hosted by Tax March.

This will end up in court, too. In fact, the best reason for Mitch McConnell’s rule change this month to get judicial appointments confirmed is the boom in business we can expect over the next twenty-one months … or longer.