He's commuted the sentences of 688 inmates this year alone.

Obama has eclipsed Calvin Coolidge, who commuted 773 sentences, but has yet to beat Woodrow Wilson, who holds the record with 1,366 commutations, according to P.S. Ruckman Jr., a political scientist tracking the data.

"While there has been much attention paid to the number of commutations issued by the President, at the core, we must remember that there are personal stories behind these numbers," White House counsel Neil Eggleston wrote in a blog post. 

"These are individuals – many of whom made mistakes at a young age – who have diligently worked to rehabilitate themselves while incarcerated."

The batch included 42 inmates serving life sentences. Many will not be released until late 2018 and will have to enroll in residential drug treatment programs. 

The latest round of commutations is part of Obama's effort to free prisoners serving lengthy sentences handed down during the government's war on drugs.

With less than three months left in office, Obama is speeding up use of his clemency power. But advocates are pressuring him to accelerate the process to ensure more deserving inmates have their sentences shortened.