(f) Disclosure to Committees of Congress
(1) Committee on Ways and Means, Committee on Finance, and Joint Committee on Taxation
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.
It sounds cut and dried, but is it?
This issue was explored in an article at Politifact early in the new year of 2019, in anticipation of coming events: Can House Democrats release Donald Trump's tax returns? The author, Louise Jacobson, first examines the seemingly plain meaning of 6103:
Is a request for Trump’s returns expected to be made once the Democrats take control of the House?
Yes. The lawmaker who’s in line to chair Ways and Means, Rep. Richard Neal, D-Mass., has said publicly that he plans to do so. "I think we would all be comfortable if this was done on a voluntary basis," Neal told CNN. "If they would resist the overture then I think you could probably see a long and grinding court case," he added.
Why would a "long and grinding court case" be probable, if the statute provides no grounds for refusing the request? There are general and specific reasons why any court case--something I think we can count on--could drag on past 2020. The general grounds hinge on the universally shared presumption that grants of powers, such as in 6103, presume some legitimate purpose for their exercise--even if tht purpose isn't expressed in the statute itself:
What arguments could the administration make to quash the request?
Legal scholars suggest that the case, if it materializes, may hinge on whether the request is considered to be for a legitimate congressional purpose or whether it’s just a ploy to embarrass the president.
"Everybody agrees that whatever the tax code might say, Congress has to have a legitimate purpose for an inquiry," Grewal said. "But there’s a point of contention about whether there would be a legitimate purpose for such a request in this case."
What's special about "this case"? That gets to the specific reasons--the fact that Trump is not Joe Blow, he's President of the United States. This is the angle that David Rivkin and Elizabeth Foley explore in an op-ed piece in the WSJ on 2/14/19 (subscription wall): Stop the Impeachment Fishing Expedition: Congress has no business investigating the president for conduct that occurred before he took office.
Constitutionally, it is wrong to conceive of the President as simply the highest officer within the Executive branch hierarchy. He alone is the Executive branch. As such, he is the sole repository of all Executive powers conferred by the Constitution.
When you understand that, you'll see where Rivkin and Foley and Foley are coming from when they argue--without specifically referring to the tax return issue--that some Congressional investigative steps can endanger the constitutional balance of powers. Moreover, they point out that there is legal precedent for their concern:
The president is not one among many, as are legislators and judges. Crippling his ability to function upsets the constitutional balance of power. For this reason, the Justice Department’s Office of Legal Counsel has repeatedly concluded that a sitting president may not be indicted or prosecuted. The same logic should apply to congressional investigations.
Now you see why the clear language of 6103 may not settle the issue. There are, arguably, delicate constitutional issues at stake that are of fundamental concern for the well functioning of our polity.
Rivkin and Foley develop this argument in the succeeding paragraphs. They note that the Supreme Court has recognized "a constitutionally based, although not unlimited, privilege of confidentiality to ensure 'effective discharge of a President’s powers.'” (U.S. v. Nixon, 1974) The Supreme Court has also held that "presidents and ex-presidents have absolute immunity against civil liability for official presidential acts." (Nixon v. Fitzgerald, 1982)
Here's where we get to the uncharted waters. What about investigations of activities of a President before he became president? Which is what all this investigation of Trump is (mostly) about? There is precedent, but it's limited and the Supreme Court appears to explicitly recognize that unresolved issues remain. Here I'll quote Rivkin and Foley at some length:
Congress is targeting Mr. Trump’s actions before becoming president because there are well-established constitutional limits, grounded in separation-of-powers doctrine, on its ability to investigate his official conduct. ...
Executive immunity for prepresidential activity is less clear. In Clinton v. Jones (1997), which arose out of Paula Jones’s accusation that Bill Clinton sexually harassed her while he was governor of Arkansas, the justices reasoned that Ms. Jones’s lawsuit could proceed because the burden on the presidency objectively appeared light. Specifically, because only three sitting presidents had been sued for prepresidential acts, the justices thought it “unlikely that a deluge of such litigation will ever engulf the presidency.”
The court did, however, consider the question of whether civil litigation “could conceivably hamper the President in conducting the duties of his office.” It answered: “If and when that should occur, the court’s discretion would permit it to manage those actions in such fashion (including deferral of trial) that interference with the President’s duties would not occur.”
So, Rivkin and Foley are arguing by analogy: If lawsuits could interfere with the President's duties--and the Supreme Court has recognized such interference as a legitimate concern--then why should not Congressional investigations, especially those that extend to "prepresidential activity," be treated in the same fashion? This is an unanswered question, guaranteed to reach the Supreme Court in one form or another if it is litigated.
And who better to litigate that issue than Bill Barr--a tenacious defender of the Executive Branch and a legendarily aggressive litigator?
Rivkin and Foley appear to have reached that conclusion (one, I think, shared by Executive Branch powers heavyweight Jack Goldsmith, cf. If Confirmed, Barr Will Be The Attorney General In Full) ahead of us, but it's nice to be in good company:
As William Barr begins his term as attorney general, House Democrats are aiming a “subpoena cannon” at President Trump, hoping to disable his presidency with investigations and possibly gather evidence to impeach him. ...
To protect the separation of powers, the president should defy all demands for information about his prepresidential activities. If Congress or private litigants seek to enforce these demands, the Justice Department should move to stay these proceedings while Mr. Trump is in office. If Democrats want to remove Mr. Trump from office, there are two legitimate ways to do so: By defeating him at the polls in 2020 or through properly conducted impeachment proceedings based on evidence of “high Crimes and Misdemeanors” committed while in office.