While many critics expressed outrage at his pardoning decisions, the custom – as outlined in the Constitution and unique to the commander in chief – has long drawn staunch condemnation.
"Presidents have often made controversial clemency decisions for what they believed were the right reasons," Spencer Critchley, Democratic communications consultant and author of "Patriots of Two Nations: Why Trump Was Inevitable & What Happens Next," told Fox News. "Clemency is supposed to be granted only when the scales of justice are out of balance."
In addition to signing off on pardons for convicted felons such as George Papadopoulos – a 2016 Trump campaign aide who became embroiled in the Russia investigation – and former California Congressman Duncan Hunter, Trump drew particular backlash from human rights activists for reprieving four private guards for Blackwater.
They were convicted six years ago of killing 14 Iraqi civilians and wounding 17 more in what authorities claimed was an "unprovoked ambush" on Baghdad's Nisour Square in 2007.
The contractors were all issued sentences varying from 12 years to life behind bars. However, supporters of the men contend that the investigation was contaminated, and the punishments handed down were too harsh.
So ultimately, how does the whole process work? Who gets pardoned and how?
Individuals, or their lawyers, can submit a petition to the pardon attorney's office at the Department of Justice (DOJ). Legal experts conjecture that it has always been a notoriously secret, arbitrary process. Many of the most egregious cases exemplifying miscarriage of justice never even make it to the White House for presidential review.
David M Schwartz, a Brooklyn-based attorney who last week successfully had the sentence commuted for his client Irving Stitsky – the former managing partner of Cobalt Capital Funding, who was sentenced in 2010 to 85 years in prison on fraud charges – told Fox News that in this cycle, there have been about 18,000 pardon requests.
"From our standpoint, pardon applications are an extension of legal advocacy in the courts. All very similar papers that were argued and filed in court are the basis of the pardon application," he said. "Every president makes controversial pardon decisions, and they usually stem from personal relationships."
But of those 18,000, only a sliver will make their way to the Oval office. According to one convicted white-collar criminal, who completed a yearslong stint behind bars in 2017 and submitted his own request-for-pardon package two years ago, he consulted legal experts who said that it would cost around $25,000 to fully prepare the pardon package. An additional $100,000 would then be needed for lobbying-like purposes to ensure it reached "the right people."
"I haven't heard anything, no confirmation or acknowledgment or anything since I sent it," the source, who spoke on the condition of anonymity, continued. "I just didn't have the money."
In recent months, Democratic lawmakers – led by California Rep. Adam Schiff – have been pushing to pass the Protecting Our Democracy Act, a piece of legislation that would establish a list of transparency requirements such as disclosure documents in a quest to avoid "self-serving" uses of the president's mercy function.
Moreover, the DOJ has been investigating whether bribes were offered to White House officials to secure a pardon or commutation of sentence for an unnamed individual. No indictments have been issued to date.
"Legally, there is essentially no requirement for a professional process except that the president can only pardon federal offenses. In the modern era, presidents have had the White House counsel do extensive work to validate and make a case for each pardon," explained Matthew Schmidt, a national security and political science coordinator at the University of New Haven. "That doesn't mean that political donors don't get a special look or that pardons granted don't also have political benefits."
Schmidt also underscored that while it is different for each president, there is always a slate of "hidden lobbying that happens."
"It's important to remember, however, that many pardons are granted in cases of wrongful conviction and other commutations for reasons of human rights," he said. "Much of the work the counsel's office does is in vetting these kinds of cases, many of which are denied and reargued year after year by advocacy groups."
Trump's headline-generating whirl of pardons in his presidency's twilight weeks follows several other judgments over the past four years. Trump's first use of the pardon power was in late 2017 when he pardoned former hardline Arizona Sheriff Joe Arpaio, convicted of contempt of court for eluding a judge's order to stop racially profiling Latinos. The following year, he pardoned Scooter Libby, the former chief of staff to former Vice President Dick Cheney convicted of perjury and obstruction regarding the CIA operative Valerie Plame's ousting.
Yet, such contentions are hardly new.
Founding father Alexander Hamilton first proposed the president be allocated such authority at the 1787 Constitutional Convention, underscoring later that the pardons or sentence reduction may "restore the tranquility of the commonwealth" in an epoch wracked by rebellion.
Thus, Article ll of the Constitution went on to denote that the president has the "power to grant reprieves and pardons for offenses against the United States." Presidents can only pardon federal crimes and can do so in four ways: erase the crime altogether, reduce or scrub the sentence via commutation, free an individual from federal prison, or grant respite – halt a person's pending sentence for the period of time.
Eight years after the landmark convention, President George Washington pardoned two men who had masterminded the 1794 Whiskey Rebellion in Pennsylvania in opposition to high federal tax on spirits. He then pardoned the remaining insurgents on the last day of his time in office in 1797.
In 1800, President Thomas Jefferson pardoned those jailed under the 1798 Sedition Act, the piece of legislation that criminalized defaming the government. In 1858, President James Buchanan promulgated sweeping pardons for members of the Church of Jesus Christ of Latter-day Saints following a deadly one-year Utah war against U.S. law enforcement. President Andrew Johnson added to a growing pile of controversial presidential pardons when he extended a wide-ranging pardon to former Confederates.
Debate deepened in the 20th century when President Richard Nixon in 1971 mandated the release of Lt. William Calley following a conviction for his role in the 1968 massacre of 22 civilians by U.S. forces in My Lai, South Vietnam. A month after his resignation amid the Watergate scandal, successor Gerald Ford spurred another wave of outrage by signing an unconditional pardon for all offenses Nixon may have committed.
In 1977, on his first day in the White House, President Jimmy Carter offered another ire-raising preemptive pardon on all those who dodged the Vietnam War draft. In 1992, President George H.W. Bush came under fire for pardoning former defense secretary Caspar Weinberger and five others for their role in the Iran-Contra Affair, which entailed selling arms to Iran even while it was under embargo during the Reagan administration.
His successor, President Bill Clinton, then put into motion some of the most eyebrow-arching pardons of all, including billionaire fugitive and tax evader Marc Rich and his ex-wife Denise Rich. They were known to have been bountiful Democratic donors to both Clinton and his wife, Hillary. Also, he issued prison commutations to 16 members of the FALN, a Puerto Rican terrorist outfit that had detonated more than 100 bombs throughout the '70s and '80s.
Then in his final hours in office, Clinton pardoned Patty Hearst, the publishing heiress who was kidnapped and became entangled in a radical left-wing group, and convicted terrorist Susan Rosenberg, who had legal representation known to be closely tied to the outgoing POTUS. He also pardoned his half-brother Roger Clinton for a 1985 conviction for distributing cocaine.
More than a decade later, President Barack Obama would go on to free another FALN devotee who had refused to accept Clinton's olive branch in exchange for renouncing violence, as well as commuting the 35-year sentence given to WikiLeaks source and U.S. military documents leaker Chelsea Manning.
"I believe those decisions are mostly political, and often meant to contain a message," said Carsten Pfau, political strategist and Agri Terra Managing Director.
By comparison to many of his predecessors, Trump so far has exercised his presidential pardon authority far less than most, granting around 70 to date.
"According to DOJ records going back to 1897, the fewest applications were received during George H.W. Bush's one term: 1,466. Barack Obama's two terms saw the most: 36,544," Critchley observed. "The Trump administration has given clemency by far the lowest percentage recorded by the DOJ, in many cases skipping the review process by just choosing people himself."
Nonetheless, more are excepted in the coming weeks as his single term comes to a close. But the biggest question on the minds of many political observers is whether Trump – who has consistently bemoaned unfair treatment and targeting by left-leaning lawmakers – will issue a preemptive self-pardon.
It is unchartered territory and a source of intense debate among legal scholars, although nothing in the Constitution blatantly prohibits it.