"He's been in jail for seven years over a phone call where nothing happens - over a phone call which he shouldn't have said what he said, but it was braggadocio, you would say", Trump told reporters last year.
In the early 1990s, Milken served two years in prison after prosecutors alleged his financial strategies and tactics were "criminal schemes", as described by the White House.
Trump, a Republican who has often campaigned on his claim to be fighting corruption in Washington, was vague about his reasoning for freeing Blagojevich, who was sentenced to 14 years.
Trump announced the news on the tarmac at Joint Base Andrews as he embarked on a four-day west coast swing and just hours after the White House announced the first pardon, that of former San Francisco 49ers owner Edward DeBartolo, Jr., who was convicted in a gambling fraud scandal.
"I do make his job harder", Trump said. More than a few Republicans played along, pretending that Trump really is an aggressive anti-corruption crusader - all evidence to the contrary notwithstanding.
On Tuesday, the White House announced that Blagojevich is among 11 people who will be receiving clemency. Trump praised Blagojevich at the time for having "a lot of guts" to appear on the programme.
In comments to reporters Tuesday, Trump said that Milken has "done an incredible job for the world with all his research on cancer" and that "he's suffered greatly".
President Trump says he relies on the recommendations attached to people's pardon petitions as guidance on whether or not to pardon them.
Blagojevich began serving a 14-year federal prison sentence in 2012.
On Trump's favourite news channel Fox News a year ago, Blagojevich's wife, Patti, depicted her husband as the victim of over-zealous prosecutors, drawing parallels with the president's experience during the Mueller investigation.
Blagojevich, Trump said in 2018, was convicted for "being stupid, saying things that every other politician, you know, that many other politicians say".
Blagojevich also was a contestant on Mr. But despite Trump's impromptu survey this week, there has never been a groundswell of support in IL for the ex-governor's early release.