Of all the legal threats Trump is facing, is this the one that could take him down?

Carlson said that even if Trump were prosecuted for removing classified papers from the White House, other officials who have mishandled secret material received only misdemeanor convictions and probation, such as the former CIA director David Petraeus.

Among other charges, prosecutors appear to be considering indictments under anti-conspiracy laws written to combat organised crime which potentially carry lengthy prison sentences.

The grand jury is also seeking testimony from Senator Lindsey Graham, an ardent convert to Trump who contacted Georgia officials looking to alter the vote, and the former White House chief of staff, Mark Meadows.

When Raffensperger rebuffed the demand, Trump made vague threats of charging him with a crime for failing to investigate allegations that Democrats had rigged the vote.

Raffensperger and Carr have already testified to the grand jury. Kemp is resisting a subpoena.

Trump also tried to get federal officials at the justice department to intervene. His lawyers filed a series of lawsuits making extraordinary claims of foreign interference and other conspiracy theories. All of them were dismissed.

Willis has told some of those involved in the fake electors plot that they are the target of criminal investigation by the grand jury, including the Georgia Republican party chair, David Shafer, and a state senator, Brandon Beach.

The district attorney has brought in a Rico specialist for the Trump investigation.The special grand jury can sit until next May, giving it plenty of time to gather evidence. But unlike regular grand juries, which meet for only two months and issue indictments, it can only submit a report recommending prosecution. Willis must then decide whether to follow that recommendation and appoint a regular grand jury to seek an indictment against Trump or anyone else.

Carlson predicted that if the special grand jury recommends prosecution, the district attorney will go ahead.

The Brookings Institution said that if Trump is charged with a crime, he is likely to claim that he cannot be held criminally liable for his actions as president. But it said that defence is likely to fail, because immunity from liability only extends to actions taken by the president that were within the scope of his lawful duties.