Mr Obama, 59, was preceded by Michigan governor Gretchen Whitmer, who Mr Trump has verbally attacked and who was the target of an alleged kidnap plot by a Michigan militia.
The evening as opened by Stevie Wonder, who was born in Saginaw, Michigan, and whose most celebrated recordings were made in Detroit, America’s largest black city, yet one that has seen its fortunes rise.
In addition to performing hits such as Superstitious, the 70-year-old songwriter and performer, also levelled a devastating attack at the president, over his handling of the pandemic, and of his apparent encouraging of right wing groups such as the Proud Boys, with his comment to “stand back and stand by”.
“You know what we say in the ghetto when somebody says that, right,” he said? “Watch yourself, get your ass whupped.”
He added: “The only way we're gonna win this fight, a fight against injustice, is by voting. We must vote justice in and injustice out.“
These are the very last days of campaigning, and along with states such as Florida and North Carolina, the election outcome will likely be decided by what happens in the upper midwest states of Pennsylvania, Wisconsin and Michigan.
The president has also been blasting his way through the midwest, and will hold rallies in Michigan on Sunday, and again on Monday night, on the very eve of the election.
At a small event in Newtown, Pennsylvania, on Saturday, Mr Trump mocked his opponent for his criticism of the administration's record of fighting the coronavirus, which has killed more people in the United States than any other country.
“I watched Joe Biden speak yesterday. All he talks about is COVID, COVID. He's got nothing else to say. COVID, COVID,” said Mr Trump.
Four years ago, Mr Trump flipped Michigan, Wisconsin and Pennsylvania, all with them with narrow margins on his way to claim the White House. He won Michigan by less than 11,000 votes; the latest polls give Mr Biden an advantage of 6.5 points.
“I think we are living in profound times,” said 28-year-old Calyssa Zellars, a lawyer, saying she was voting for Mr Biden and his running mate, Kamala Harris. “This is the most signifiant election of my life.”
When the former president introduced his former vice president to the stage, he did as “the next president of the United States”. Mr Obama was the 44th president, while Mr Biden would be the 46th.
Mr Biden, 77, appeared sprightly as he made his way to the stage and made a “air elbows” gesture, to the man around whom he has built a considerable fraction of his appeal to the country, as someone who could turn back the clock to times of less chaos.
With something of a spring in his step, he made fun fun of Mr Trump’s hairstyle, his cozy relationship with Russian president Vladimir Putin, and Mr Trump's description of himself as a “perfect physical specimen”.
Mr Biden said: “The president likes to portray himself as a tough guy - tough guy, my word.”
Yet, if Mr Biden was efficient, the presence of Mr Obama on stage, underscored the power and personality he has, that even the former vice president would not claim to match. Many have pointed to an enthusiasm deficit among Democrats, when compared to candidates such as Bernie Sanders
Amy August was leaning against her car, listening to Mr Biden, as a huge American flag blew and and fluttered, the fabric being moved by powerful fans, set up to create a theatrical backdrop. She had come to the event with her daughter, Catherine, 18, who was voting for the first time.
Was she concerned that Mr Biden may not have the same charisma at Mr Obama?
“Anyone but Trump,” she said. “Or even, any thing but Trump.”
Additional reporting by agencies
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