Trump told reporters at Joint Base Andrews that Blagojevich "served eight years in jail. It's a long time to go."
Trump publicly hinted he would use his clemency powers for Blagojevich, a Democrat, in August. But he faced sharp blowback from some conservative members of Congress, including from Illinois, as well as from some White House advisers who said it wouldn't play well.
Internally, the effort to pardon or commute Blagojevich's sentence was championed by Jared Kushner, who has led the administration's criminal justice reform efforts.
Blagojevich appeared on Trump's boardroom reality show NBC's "Celebrity Apprentice" in 2010 but was fired by the future president before the final round.
Several Republican lawmakers aired their concerns in phone calls to acting White House chief of staff Mick Mulvaney and White House counsel Pat Cipollone. Two Republicans, Reps. Darin LaHood and Mike Bost, directly appealed to Trump not to use his clemency powers for Blagojevich.
By August, the White House had already been working for several months on vetting Blagojevich's case. The President first raised it in 2018.
Trump has suggested in his public comments about the case that he believes Blagojevich was simply doing what all politicians do.
"I would think that there have been many politicians -- I'm not one of them, by the way -- that have said a lot worse over the telephone," he said last year.