President Trump is being urged to use his remaining time in office to grant preemptive pardons to people close to him, including family members and maybe even himself.

Sean Hannity, whose Fox News program is closely followed by Trump, said on his radio show this week that the president, "out the door, needs to pardon his whole family and himself because they want this witch hunt to go on in perpetuity, they're so full of rage and insanity against the president."

Hannity likely was referring to the prospect for a post-presidential prosecution of Trump, who faces serious potential legal issues once he is out of office and no longer enjoys the privilege of not being indicted by federal prosecutors.

President-elect Joe Biden has said he'd let professionals within the Justice Department assess whether a case is merited against Trump, and that decision — which would be unprecedented — is one of the toughest facing the department in the new administration.

A presidential preemptive pardon sounds unusual, but it has been done before, most famously when President Gerald Ford pardoned Richard Nixon, who resigned because of the Watergate scandal in 1974 but had not been charged with any crimes.

"A preemptive pardon is a presidential pardon granted before any formal legal process has begun," American University professor Jeffrey Crouch tells NPR.

Read the text of Ford's pardon of Nixon here.

In an email, Crouch, author of The Presidential Pardon Power, says that "someone must have committed a federal offense, but as soon as that happens, the president can grant them clemency. He does not need to wait until the alleged offender is charged, stands trial, and so on."

Crouch continues: "These pardons are not common, but they do happen occasionally."

Accordingly, Trump could "pardon his children, his aides, his supporters, and so on for federal offenses and be on firm legal ground," Crouch says. "The really unclear scenario would be if he attempted to pardon himself."

The man in the mirror

Trump has asserted he has the power to pardon himself but has said he didn't need to use it because he hasn't done anything wrong. Not only might his denial about any lawbreaking be complicated by events following his departure from office, the merits of a self-pardon are controversial and have never been tested in court.

And although the potential legal problems facing Trump are thought to be well understood, at least in principle, it's not clear what if any criminal offenses with which Trump's children might be charged.

Donald Trump Jr. was investigated by special counsel Robert Mueller over his contacts with Russians during the 2016 Trump campaign, but no charges were brought. Ivanka Trump, her husband, Jared Kushner, and the president's younger son Eric have been the subjects of allegations of various kinds, but none that so far have risen to the level of a potential prosecution.

Trump could also be considering a pardon for attorney Rudy Giuliani, according to one report.

How pardons work

Specialists point out that even if the public may not be aware of all the actions involving the prospective recipients of potential pardons, there's an important distinction:

A president can protect someone from being prosecuted for something they've already done, even if it doesn't come to the attention of prosecutors later — but not protect someone from being prosecuted for something they haven't yet done, or from being prosecuted by state or local authorities.

Bernadette Meyler, a professor at Stanford Law School, says the precedents in these cases go back to the earliest days of the republic, when President Washington used his pardon powers to grant amnesty to some of the conspirators in the Whiskey Rebellion.

"The Supreme Court interpreted the pardon power to include amnesty in cases like United States v. Klein," she says. "So what Trump would probably do is something like Ford's pardon of Nixon, which described a period of time and immunized Nixon against prosecution for activities undertaken during that time."

But that wouldn't be a lifetime Get Out of Jail Free card.

Meyler, author of Theaters of Pardoning,notesthat "such pardons could not cover future events."

The Department of Justice's Office of the Pardon Attorney notes this: "It would be highly unusual" for a president to issue preemptive pardons.

But it also says "there have been a few cases where people who had not been charged with a crime were pardoned, including President Gerald Ford's pardon of President Richard Nixon after Watergate, President Jimmy Carter's pardon of Vietnam draft dodgers and President George H.W. Bush's pardon of [onetime Defense Secretary] Caspar Weinberger. President Donald J. Trump pardoned Joseph Arpaio after he was charged and convicted, but prior to sentencing."

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