In a newly released video, the former president claimed Mr Trump had “violated” a host of democratic norms, including the rule of law, freedom of the press, and “not trying to intimidate enemies by threatening them with the criminal justice system” – a reference to Mr Trump’s threats to jail his former election opponent, Hillary Clinton.
The only check on the White House, he claimed, was to elect other officials who would “stand up for American values and American ideals”. He added that he believed Mr Trump had failed to get right “basic stuff” including transparency and declaring conflicts of interest.
While celebrated now by liberals yearning for a Democrat in the White House, Mr Obama has been criticised in the past for aggressively prosecuting those who leaked government information to the press. The Obama administration prosecuted a record nine cases involving whistleblowers and leakers – more than all administrations before him combined.
The former president has previously been more oblique in his criticism of his successor. Now, however, the Democrats are pushing to regain control of the House of Representatives in November’s mid-term elections and Mr Obama has announced his intention to hit the campaign trail.
Mr Trump intends to do the same, reportedly planning to be on the road for 40 days before November’s polls.
Saturday’s video, produced by NowThis, was part of Mr Obama’s campaign to mobilise younger voters.
He kicked off the campaign on Friday with a speech at the University of Illinois-Urbana Champaign, where he criticised Mr Trump by name for the first time since the 2016 election. The president, he said, was “capitalising on resentment that politicians have been fanning for years”.
Mr Trump responded by saying he had tried to watch the speech, but fell asleep.
“I think [Mr Obama] is trying to take credit for this incredible thing that’s happening to our country,” he added, referring to recent increases in the employment rate.
Mr Obama continued his line of attack in the video, which was shot on the university campus after his speech.
The former president was set to headline a rally for Democratic candidates in California on Saturday, and an event for the Democratic gubernatorial candidate in Ohio on Thursday, according to CNN. He is due to travel later this month to New York, to attend a fundraiser for the National Democratic Redistricting Committee.