You had me at "I'll read it to you," Nancy.

[gratuitous]

35. Nobody is saying that Congress has unlimited power

But the U.S. Code specifies that the chairmen of three specific committees (one House, one Senate, one Joint) have the power, "Upon written request from the chairman of the Committee on Ways and Means of the House of Representatives, the chairman of the Committee on Finance of the Senate, or the chairman of the Joint Committee on Taxation, the Secretary shall furnish such committee with any return or return information specified in such request, except that any return or return information which can be associated with, or otherwise identify, directly or indirectly, a particular taxpayer shall be furnished to such committee only when sitting in closed executive session unless such taxpayer otherwise consents in writing to such disclosure."

There are no limitations on that power, no reason needs to be given by any of the specified chairmen under subsection (f). The House Ways and Means Committee can review the requested returns in closed executive session, and may not publicize the return without the consent of the taxpayer whose return was requested. I didn't see any penalty or sanction should the committee reveal the contents of a requested return outside a closed executive session (which is not to say that there isn't a penalty or sanction). Considering the way the Trump administration has conducted its affairs, it would be fitting for it to be treated in the same cavalier manner it has treated the rights of individuals.

Oddly, under subsection (g)(1)(D) pertaining to the Executive or a cabinet Secretary, a request for a taxpayer's return must state a specific reason for the request. So clearly Congress knew how to write legislation so that a reason for a request for taxpayer information could be required (Executive) or not required (Chairman of the House Ways and Means Committee, the Senate Committee on Finance or the Chairman of the Joint Committee on Taxation).