Last month, a federal court held that President Trump cannot block a House subpoena targeting Trump’s accounting firm, which seeks many of Trump’s financial records. On Monday, Trump’s lawyers filed a brief asking a federal appeals court to reverse this decision, and their very first argument is a doozy.

The brief opens with a direct appeal to the Supreme Court’s corrupt self-interest.

Trump has no legal basis to resist the subpoena. As Judge Amit Mehta explained in his opinion ruling against Trump, “so long as Congress investigates on a subject matter on which ‘legislation could be had,’ Congress acts as contemplated by Article I of the Constitution.” In this case, the financial documents the House seeks “will aid its consideration of strengthening ethics and disclosure laws, as well as amending the penalties for violating such laws” — among other things.

Moreover, even if Congress was not contemplating legislation to shore up ethics laws against a corrupt president, the Supreme Court explained in a 1957 opinion that Congress may “inquire into and publicize corruption, maladministration or inefficiency in agencies of the Government.”

Faced with a bevy of precedents establishing that Trump has no legal case whatsoever, Trump’s lawyers appeal instead to a bizarre kind of solidarity between the sitting president and the members of the Supreme Court — protect my corruption, the lawyers write, and you’ll also shield corruption by the justices themselves.

“Replace ‘President’ with ‘Justices,'” Trump’s lawyer’s write, “and the ruling below would, without question, authorize a congressional subpoena for the Justices’ accounting records — even for many years before they joined the Court.”

It’s an audacious play. For one thing, Congress absolutely should have the power to investigate a sitting justice’s finances under the appropriate circumstances. To give just one example, the Constitution gives the House of Representatives “the sole power of impeachment,” and that power extends to members of the Supreme Court.

In the context of legislation, the Supreme Court explained in Eastland v. U.S. Servicemen’s Fund, “the power to investigate is inherent in the power to make laws because ‘[a] legislative body cannot legislate wisely or effectively in the absence of information respecting the conditions which the legislation is intended to affect or change.’” A similar logic applies to the impeachment power. If Congress cannot investigate federal officials who may be worthy of impeachment, it won’t be able to make wise or effective decisions about when impeachment is warranted.

If the House had good reason to believe that a sitting justice was engaged in corrupt dealings — perhaps the justice is deciding cases in a way that benefits their own stock portfolio — then the House absolutely should have the power to investigate that justice.

But Trump’s lawyers are apparently betting that a majority of the Supreme Court would corruptly give themselves immunity to investigation before they require 10 of the most powerful people in the nation — the president and the members of the Supreme Court — to comply with the same rules that every other government official must obey.