President Trump this week pardoned former aide Rudy Giuliani, former White House Chief of Staff Mark Meadows and many others accused of trying to overturn the results of the 2020 presidential election.

It comes after recent clemency grants from Trump to former U.S. Rep. George Santos and an ex-CEO of a cryptocurrency exchange.

While former President Joe Biden still holds the record of 4,245 clemency actions, Trump's second-term pardons and commutations are notable for their political and personal connections to the president, says Bernadette Meyler, a professor of constitutional law at Stanford University.

"There's more of a sense of the insider pardon than we've seen previously," Meyler said.

In mid-October, Trump commuted the prison sentence of Santos, the disgraced New York Republican who pleaded guilty to wire fraud and identity theft last year.

Days later the president handed a full and unconditional pardon to Changpeng Zhao, the former CEO of Binance, who pleaded guilty to money laundering charges. Binance has ties to the Trump family's cryptocurrency business, but Trump said in an interview with 60 Minutes that he does not know who Zhao is.

U.S. presidents are given broad authority to nullify convictions or sentences for federal crimes without the involvement of Congress or the Supreme Court. The legal principle is a holdover from English law, in which the king had what was known as the "prerogative of mercy" as early as the seventh century.

While Trump has granted clemency to a wide range of people convicted of federal crimes, from nonviolent drug offenders to white-collar criminals, his first term in office was also marked by several notable pardons of political allies and grants of clemency to people whose cases were advocated for by celebrities or friends. Both of those trends have been amplified during his second term, Meyler said.

"He's much more explicit about making political statements through the use of the pardon power," Meyler said of Trump's second-term pardons and commutations. She said that includes granting clemency for people who have supported his political career as well as public statements he's made about why a particular crime shouldn't be punished.

Trump is by no means the first president to show leniency to a political ally. President Bill Clinton pardoned Mark Rich, a former hedge-fund manager whose ex-wife had donated hundreds of thousands of dollars to the Democratic National Committee, the Clinton Presidential Library and Hillary Clinton's New York Senate campaign. And President George W. Bush commuted the sentence of Lewis "Scooter" Libby, the former chief of staff to Vice President Dick Cheney.