The White House claims executive privilege over Mueller's report -- here's what happens next
US President Donald Trump has a uniquely combative relationship with the media, which he denounces as "fake news," except in a handful of cases, including his favored Fox News network (AFP Photo/NICHOLAS KAMM)

The White House has claimed executive privilege over the Mueller report, which is currently available for download or purchase in redacted form online -- so what happens next?

The Department of Justice asked the White House to invoke executive privilege over the entire report and the underlying evidence in response to the House Judiciary Committee voting to hold Attorney General William Barr in contempt for refusing to make all of special counsel Robert Mueller's findings available to legislators.

Numerous legal experts have said the executive privilege claims was ridiculous, because President Donald Trump's advisers and other White House officials have already testified and much of their testimony has already been made public.

House Democrats will almost certainly challenge the claim, which will be decided through litigation.

The executive branch may invoke its privilege to ignore the legislature or judiciary’s subpoenas or other attempts to gain information from the White House, president, aides and Cabinet agencies under two categories.

The so-called presidential communications privilege is based on the separation of powers in the U.S. Constitution, which permits each co-equal branch of government the freedom to function without interference from the other two.

The Supreme Court ruled unanimously in United States v. Nixon that there is a "presumptive privilege for presidential communications," and the District of Columbia Circuit Court established another form of privilege in 1997.

The deliberative process privilege established in that ruling is based on the common-law notion that government officials should be free to privately discuss their actions before making a decision.

That privilege is broader in application, but applies only to documents and discussions before a decision is made, while presidential privilege may also apply to final decisions.

However, the power of Congress to obtain information and investigate is very broad.

The Supreme Court has established and upheld that power as essential to legislative oversight, and disputes between Congress and the president over executive privilege are typically decided through negotiations between the two co-equal branches.

That's what makes Barr's sweeping request for executive privilege -- and the White House's subsequent claim -- an unusual "escalation," as House Democrats have termed the move.

“If allowed to go unchecked this will mark the end of congressional oversight,” said Rep. Jerry Nadler (D-NY), chairman of the House Oversight Committee. “No person should be allowed to be above the law.”

Barr has offered Democrats a less redacted version of Mueller's report, which the House majority has rejected, and the legislative branch and executive branch could continue negotiations for releasing unredacted report and its underlying evidence.

If those negotiations fail or Democrats feel they're unlikely to move forward, they could kick the conflict into federal court by filing a lawsuit.

That litigation could then wind up before the U.S. Supreme Court.