What do a late, legendary boxer, an incarcerated former governor and a lifestyle mogul perfecting her selfie have in common?

President Donald Trump has deemed them all — Muhammad Ali, former Illinois Gov. Rod Blagojevich and Martha Stewart — potentially worthy of his pardon power, alongside "literally thousands" of other names.

"There will be more pardons," the president said earlier this month, days after commuting the sentence of a grandmother serving life without parole for a nonviolent drug crime at the urging of reality TV star Kim Kardashian West. "We are looking at literally thousands of names of people that have come to our attention that have been treated unfairly, or where their sentence is far too long."

Here's a handy guide to the seven people Trump has pardoned or given a commutation to so far, and who could be up next.

Who has Trump granted clemency?

Joseph Arpaio: The former Arizona sheriff who was convicted of criminal contempt for ignoring a judge's order not to detain suspected undocumented immigrants received Trump’s first pardon in August 2017. Arpaio was an ardent supporter of Trump's presidential campaign.

Sholom Rubashkin: The former chief executive of a kosher meatpacking plant, convicted of money laundering and serving 27 years, received a commutation in December 2017, marking the first time the president used his executive power to reduce a sentence. The White House said at the time they were encouraged by bipartisan leaders from across the political spectrum, including Rep. Nancy Pelosi, D-Calif., and Sen. Orrin Hatch, R-Utah.

Kristian Mark Saucier: The Navy sailor was pardoned after spending a year in federal prison for illegally taking photos of classified areas of submarines. The president mentioned Saucier's case on the campaign trail.

I. Lewis "Scooter" Libby: The former aide to Vice President Dick Cheney had been convicted of lying to federal agents and obstructing justice.

Jack Johnson: The famous boxer received an unusual posthumous pardon for a 1913 conviction of a charge related to an interracial relationship. His case was brought to Trump's attention by "Rocky" actor Sylvester Stallone.

Dinesh D'Souza: The conservative filmmaker was convicted of violating campaign finance laws. Sen. Ted Cruz, R-Texas, said he suggested that Trump pardon D'Souza.

Alice Marie Johnson: A grandmother whose life sentence without parole was commuted after the punishment for her nonviolent drug crime caught the attention of Kim Kardashian West, who lobbied the president personally on Johnston's behalf.

Who could be granted clemency next?

Trump’s remarks have sparked a flurry of petitions, with celebrities and talking heads tossing potential names around, too.

Former Gov. Rod Blagojevich: The Illinois Democrat was convicted on more than a dozen public corruption charges related to his attempt to sell the Senate seat vacated by Barack Obama after he was elected president. Trump himself floated Blagojevich for a pardon, while wife Patti Blagojevich has appealed on her husband's behalf in the media.

Martha Stewart: The lifestyle mogul was convicted of insider trading crimes and served time. The president said he felt she was treated unfairly and that he was considering a pardon.

Muhammad Ali: The boxing champion was convicted of draft dodging during the Vietnam War, but his family's attorney said they had not appealed for a posthumous pardon, and that it would be "unnecessary" because the Supreme Court had overturned his conviction.

Matthew Charles: There’s a popular petition advocating for clemency for this Nashville grandfather, who was sent back to jail this year after authorities determined his initial release was granted in error. He had rebuilt his life after his 2016 release, complete with a job, an apartment, a car, and a girlfriend.

Clint Lorance: The Army Lieutenant is serving time for ordering his men to shoot at three unarmed Afghanis; two died. Lorance said he was defending his platoon, and conservative commentators have said he was wrongly punished.

Hip-hop artists: Kim Kardashian West gave Trump son-in-law and senior adviser Jared Kushner a list of names of people she'd suggest for clemency, according to Vanity Fair, which included several hip-hop artists.

An NFL player's brother: The president said he'd ask the pro-footballers for suggestions on who should be granted clemency. Former Giants kicker Lawrence Tynes suggested his brother, Mark R. Tynes, who he said in a tweet is serving 27 years for selling marijuana.

Dwight Hammond Jr. and Steven Hammond: The father and son Oregon ranchers were convicted in 2012 of arson on federal lands and served the three months and one year, respectively. A federal appeal challenged their short sentences and sent them back to jail in 2016, to finish the mandatory minimum five-year of jail time associated with their charges. Their case is under consideration, according to The Washington Post.

David Petraeus: Sen. John Cornyn, R-Texas, suggested Trump pardon the retired general who was convicted of leaking military secrets to his mistress biographer in 2015.

Michael Cohen: Asked if he’d pardon his former lawyer now under investigation for bank fraud and campaign finance violations, Trump said, "Stupid question."

How do pardons and commutations typically work?

The U.S. Constitution says the president "shall have power to grant reprieves and pardons for offenses against the United States." Pardons are the president's forgiveness for federal crimes; commutations are not.

Presidents receive thousands of applications for pardons or commutations during their terms. During the Trump's first 16.5 months in the White House, he has already received 2,853, according to the Department of Justice's Office of the Pardon Attorney statistics. There are also more than 9,000 applications pending from the previous administration, as well, according to the DOJ statistics.

There are some general guidelines for pardons: Individuals must wait five years after their release or conviction, whichever is later, and must show that they've been rehabilitated and regret their crimes. Prosecutor and judge recommendations are taken into account, as is the petitioner's actual need for a pardon, like if the past conviction prevents the individual from receiving employment licensing.

Commutations are traditionally considered in regard to severe or undue severity of sentence, illness or old age, or service to the government, the Office of the Pardon Attorney notes.

There's no requirement for the president to follow these guidelines. For instance, Arpaio had not yet been sentenced for his crime before his pardon, which defied the typical waiting period.

Trump isn't the first to issuecontroversial orguideline-defying pardons: President Barack Obama commuted the sentence of Chelsea Manning after she served seven years of a 35 year prison term for leaking government secrets, and pardoned retired Gen. James Cartwright before he was sentenced by a federal judge. Cartwright pleaded guilty to lying to the FBI about leaking information.

Is there a theme emerging to Trump's pardons?

There's a common thread to the president's pardons so far.

“I thought he was treated unbelievably unfairly," Trump said of Arpaio.

D'Souza was "treated very unfairly by our government!" Trump said in a tweet announcing that pardon.

On pardoning Libby, Trump said, "For years I have heard that he has been treated unfairly.”

It's a common theme that might help predict future pardons, too.

Speaking on Air Force One about pardons, Trump said, "I think to a certain extent Martha Stewart was harshly and unfairly treated. And she used to be my biggest fan in the world … before I became a politician. But that’s OK, I don’t view it that way.”

Might Trump pardon anyone involved in the Russia probe?

Several Trump campaign aides, including one who went on to work at the White House, have been accused of serious crimes uncovered amid a federal investigation into Russian interference in the 2016 election, which includes investigating possible collusion between Trump's campaign and the Kremlin.

The president could indeed pardon those individuals, though Trump attorney Rudy Giuliani reportedly said the president would wait until the completion of the probe to do so.