On Monday, Treasury Secretary Steven Mnuchin informed House Ways and Means Committee Chair Richard Neal (D-Mass.) that he will not willingly hand over President Trump's tax returns, as requested under a 1924 law that clearly states he "shall" turn them over. House Minority Leader Chuck Schumer (D-N.Y.) got out his highlighter:

Secretary @StevenMnuchin1, what part of “shall” do you not understand?



From 26 U.S.C. Section 6103 (f): pic.twitter.com/S8ejshcjY5 — Chuck Schumer (@SenSchumer) May 7, 2019

To put it bluntly, Mnuchin appears to be breaking the law. He doesn't frame it that way, of course. In a one-page letter to Neal, he said that after consulting with Trump's Justice Department, "I have determined that the committee's request lacks a legitimate legislative purpose" and "the Supreme Court has held that the Constitution requires that congressional information demands must reasonably serve a legitimate legislative purpose."

The 1924 law does not require any legislative or policy rationale for obtaining tax returns, but some legal experts agree that a string of court opinions demanding legislative reasons could pose a significant hurdle for Democrats if they sue Mnuchin, Politico reports. Neal gave one policy reason, and he could presumably give more.

This also has direct bearing on tons of legislation, from HR 1 to sanctions against Russia to trade relations with China to the Trump tax bill—all under Ways & Means purview. Perhaps no tax returns in history have had the sprawling legislative relevance as do Donald Trump’s. https://t.co/fx5O5fIklS — Jesse Lee (@JesseCharlesLee) May 6, 2019 There is a law. It is written down. It says Mnuchin shall furnish the returns upon written request. Mnuchin is breaking this law. We don’t need to ask whether there is a legitimate legislative purpose. That’s for investigations where there’s no existing law. Here, there is a law. https://t.co/aR5Wc7FTxq — southpaw (@nycsouthpaw) May 6, 2019

This dispute may very well be decided by the Supreme Court, eventually. For more context, read Paul Blumenthal's short, engaging history of how and why Congress gave itself the power to see anyone's tax returns in 1924. Peter Weber