Any day now, a federal court in Washington, D.C., could force the Obama administration to disclose thousands of documents in a suit challenging the takeover of Fannie Mae and Freddie Mac during the 2008-09 housing crisis. The Fairholme Funds argue that the Obama administration acted without authority when it wiped out the value of equity and shareholders and took full control of the two government-sponsored enterprises. But an even greater constitutional principle is at stake: The White House is attempting to double down on its unprecedented taking of property by concealing from the federal courts information necessary to uphold the law.

In 2008, with financial markets in free fall, federal officials moved to prevent the collapse of the enterprises, which buy mortgage loans from banks, bundle them into securities, and sell them to investors. The Housing and Economic Recovery Act went into effect, providing them with $187.5 billion in public funds and placing them in conservatorship under a new Federal Housing Finance Agency. In 2012, when Fannie and Freddie were again generating profits, the Treasury Department implemented what has become known as the Net Worth Sweep. Under the amended terms of conservatorship, the profits of the two enterprises are diverted to the government’s general revenue stream, with nothing going to Fannie and Freddie shareholders. The arrangement remains in effect.

In 2013, Fairholme Funds filed suit in federal court, alleging the government exceeded its authority and vacated the law’s requirement to preserve and conserve the assets of the enterprises, which are privately held companies. Essentially, the lawsuit alleges that the agency took the property of Fannie Mae and Freddie Mac’s investors, for which the Constitution’s Fifth Amendment requires the government to pay “just compensation.”

The case has landed before Judge Margaret Sweeney of the U.S. Court of Federal Claims. As the case has proceeded to discovery, where both sides must provide all information relevant to the case, the Obama administration has dug in its heels. It has invoked a variety of executive privilege claims, focusing on the “deliberative process” of government, to conceal its reasons for seizing investors’ property.

The Obama administration’s claims mark yet another step in its misuse of presidential power. Presidents have invoked executive privilege rarely. Richard Nixon invoked it just six times during the Watergate probe. Bill Clinton sought to invoke it 14 times during congressional queries related to the Monica Lewinsky matter. It was not until the landmark United States vs. Nixon case in 1974, however, that the Supreme Court rejected the claim of “an absolute privilege of confidentiality for all presidential communications.” The president’s general interest in candor in policy discussions would give way before the legitimate needs of the federal judiciary to perform its own constitutional function — that of deciding cases under federal law.

If the Obama administration persists in its efforts to block judicial understanding of its seizures of Fannie Mae and Freddie Mac, it would surely lose under the Nixon test. But the government has invoked this privilege in such a haphazard and flawed manner that Judge Sweeney should toss out the claim before it even reaches a level of constitutional seriousness. For example, the government on the one hand claims that the housing finance agency cannot be considered the “United States” because it is merely acting as conservator of non-government business enterprises, but on the other invokes the deliberative process privilege, which belongs only to the executive branch of the government. The president cannot extend executive privilege to the operations of a government-owned corporation and its regulator in the commercial markets.

For more than a year, the sheer volume of documents for which the government has sought confidential treatment has drawn scrutiny from Senate Judiciary Chairman Charles Grassley and the media. Attorneys for Fairholme contend that the government wants 77,945 documents withheld from public view and 12,251 documents completely withheld.

The administration’s executive privilege claim is also on thin ice because of the dubious relationship between the subject matter of the material and the nation’s security or economic interests. The government has asserted the information could be “disruptive to markets.” However, it is difficult to imagine how discussions by officials as far back as eight years ago and emails on matters as mundane as daily press clips could impact today’s markets, which, by definition operate on the very latest information.

Executive privilege is available for presidents to use in highly sensitive matters, and its use is constrained by specific procedures. In the pending litigation on the Net Worth Sweep, the government has applied this privilege in an overly broad and unjustified manner. Either federal officials are trying to cover up something they know is illegal, or we are witnessing an unprecedented and disturbing obsession with secrecy.

Let’s hope Judge Sweeney continues to chip away at the wall the government has erected.

John Yoo has been a professor of law at the UC Berkeley School of Law since 1993. He served as a deputy assistant attorney general in the Office of the Legal Counsel of the U.S. Department of Justice from 2001 to 2003, where he worked on constitutional and national security matters. To comment, submit your letter to the editor at www.sfgate.com/submissions