Noah Bookbinder, Gabe Lezra and Conor Shaw

Opinion contributors

President Donald Trump has gone to great lengths to avoid the accountability and transparency that are crucial to our democracy, and he’s at it again. On Fox News Sunday, acting White House Chief of Staff Mick Mulvaney claimed that Congress will “never” receive Trump’s tax returns.

Gone is the president’s repeated assertion that he would disclose his tax returns if only he were not under audit (never a legitimate excuse); now his acting chief of staff is saying that Congress will not and should not get the returns at all. Mulvaney is wrong. In fact, the tax code mandates disclosure of returns upon written request from any one of three congressional committees.

Even worse, Mulvaney made the alarming claim that not disclosing the president’s tax returns was justified because the issue was "already litigated during the election. Voters knew the president could've given his tax returns, they knew that he didn't, and they elected him anyway."

The president’s solemn duty to take care that the laws are faithfully executed has apparently yielded to the view that a president’s election to office is a license to disregard the law entirely. And, actually, Trump told voters many times that he would eventually release his taxes.

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The new request for Trump’s various returns was neither impulsive nor misguided: Rep. Richard Neal, chairman of the House Committee on Ways and Means, held a hearing on this authority (at which one of us testified) in February and waited until last week to formally issue the request.

A straightforward request for returns

Internal Revenue Code Section 6103(f)(1) authorizes the Ways and Means Committee and two other congressional committees to obtain the tax return information of any taxpayer from the Treasury Department. Congress gave itself this power in 1924 in response to abuse by the executive branch. After then-Treasury Secretary Andrew Mellon’s decision to retain his interests in his sprawling business empire while in office, Congress determined that it should be able to obtain private tax returns. This authority was created for the precise reason that it is being invoked today: to give Congress a way to get the information it needs to conduct oversight.

The relevant section of the tax code is not complicated. It says that “upon written request from the chairman of the Committee on Ways and Means of the House of Representatives ... the secretary (of the Treasury) shall furnish such committee with any return or return information specified in such request." The words “shall furnish” leave no room for ambiguity, and the law lists no exceptions. There is no valid legal basis for Treasury not to disclose returns that Neal requested in writing.

Contrary to Mulvaney’s assertions, a congressional request for the tax returns of the president and eight entities that he stands to profit from is actually unremarkable — except for the fact that anyone had to ask in the first place.

Tax returns could reveal conflicts or even fraud

President Trump’s nonstop affronts to ethics and transparency are at this point almost too many to recount. After becoming the first president in more than 40 years not to disclose at least portions of his tax returns to the American people, he refused to divest from his businesses. While in office, he has taken near constant trips to his private businesses, has used his office to promote those businesses, and has given unique access — including appointments and unofficial advisory positions — to his paying customers. Foreign governments and interest groups know they can curry favor by bringing business to the president’s properties, and they have been happy to oblige.

For these reasons, Neal's request for Trump’s tax returns and those of eight affiliated entities serve numerous valid oversight interests. They could shed light on a number of critical questions, including whether President Trump or his businesses are receiving income from foreign sources, whether he has any previously unknown financial conflicts of interest that could be influencing his decisions as president, and whether he personally benefited from the massive overhaul of the tax code that he and congressional Republicans enacted in 2017.

The returns might also shed light on actual or potentially fraudulent charitable giving, a genuine issue after Trump agreed to permanently shutter the Donald J. Trump Foundation in connection with an ongoing investigation by the New York attorney general. And the returns might also reveal whether the president paid his fair share of taxes, a legitimate question given the blockbuster report that President Trump’s family appears to have engaged in an elaborate, decades-long tax avoidance scheme.

Businesses offer vast chances for influence

Neal also requested the individual returns of eight of Trump’s businesses, including the Donald J. Trump Revocable Trust, the umbrella entity that holds all his other businesses. This is a crucial addition. Based on what we know today, President Trump’s businesses have provided a vast array of opportunities for those seeking to influence him. The public record discloses more than 1,400 points of contact involving the government, those trying to influence it, and the Trump Organization during President Trump’s first two years in office.

The values in question here transcend Donald Trump. At stake is not just the ability of Congress to obtain information crucial to its responsibility to conduct oversight, but also the need to prevent Trump’s rejection of a decades-old norm from becoming the new normal.

That’s why our organization, Citizens for Responsibility and Ethics in Washington, has called on all candidates for president to voluntarily disclose 10 years of tax returns so that the American people can compare what each candidate has released and read the returns for themselves.

So far, four people who have announced their candidacy for 2020 have met this test: Sens. Kirsten Gillibrand, Amy Klobuchar and Elizabeth Warren, and Washington Gov. Jay Inslee. Trump and 16 others have yet to do so. Until they do, the American people can only imagine what they might have to hide.

Noah Bookbinder is the executive director of Citizens for Responsibility and Ethics in Washington. Gabe Lezra and Conor Shaw serve as counsel at CREW. You can follow them on Twitter: @NoahBookbinder and @ConorMarcusShaw