Executive privilege: what is it and why is Trump invoking it?

Former president and his allies have used claim to block testimony and documents from January 6 investigation

Former US president Donald Trump is claiming executive privilege to stop his White House records related to January 6 being handed to a US house committee investigating the insurrection. AP

Former US president Donald Trump and his allies are locked in battles with departments and politicians over their alleged roles in the January 6 insurrection.

His former chief strategist, Steve Bannon, recently turned himself over to federal authorities after a grand jury indicted him for criminal contempt of the US Congress.

The US House committee investigating the January 6 insurrection said it would vote on a contempt report for former Trump Justice Department official Jeffrey Clark for defying a subpoena.

Mr Trump has been blocking the House select committee's efforts to receive his January 6 records, suing the national archivist. A federal appeals court heard arguments on Tuesday.

Disputes over executive privilege go back centuries, and its definition is ill-defined and markedly contentious.

What is executive privilege?

Mr Trump, Mr Bannon and Mr Clark have all sought protection under executive privilege, a power that permits the president and officials in the executive branch to withhold certain types of communication from the judiciary and legislative branches.

The power is typically claimed in the case of "certain national security needs" and when in the public interest to do so, said Mark Rozell, founding dean of George Mason University's school of policy and government.

Although not mentioned in the US Constitution, executive privilege has been considered an implied endowment to ensure that one branch of the US government does not become too powerful.

Executive privilege essentially curbs some of the power the legislative branch, Congress, has on the executive, the president.

But this power is not absolute.

In a landmark case at the height of the Watergate scandal in 1974, the US Supreme Court unanimously ruled that Richard Nixon did not have absolute privilege to withhold information.

The high court ruled that Nixon's tapes showed no danger to the US if they were turned over, dealing a fatal blow to his presidency. He resigned 16 days later.

US District Judge Tanya Chutkan, who originally refused to block Mr Trump's records, made a similar argument in her November ruling.

“Presidents are not kings and plaintiff is not president,” she said.

Do former presidents keep executive privilege?

Three years after resigning as president, Nixon challenged a law that directed he must hand over presidential papers and tapes so archivists could review them for potential judicial proceedings.

The high court ruled against Nixon's claim that handing them over would disrupt the executive branch since it had access to the documents, but simultaneously stated executive privilege did not fall on the current president alone.

"We reject the argument that only an incumbent president may assert such claims, and hold that appellant, as a former president may also be heard to assert them," the Supreme Court wrote in 1977.

Still, the Supreme Court seemed to give greater weight to the incumbent president's claim on executive privilege.

President Joe Biden waived executive privilege so Mr Trump's records may be released from the National Archives, which houses White House records.

Mr Trump sued the archivist to prevent the release.

An appellate court judge on Tuesday questioned if a former president ever overruled the incumbent's decision on which papers to be handed over.

"Is there a circumstance where the former president ever gets to make this sort of call?" asked Judge Ketanji Brown Jackson.

Whether Mr Trump's claim is valid may never be known.

With Republicans primed to retake the US House of Representatives next year, it is possible the investigation is closed before an answer is given.