The former president spoke at a drive-in rally at his first joint campaign event with Joe Biden, telling the crowd that Trump "cares about feeding his ego" while Biden "cares about keeping you and your families safe."

Wearing a black windbreaker but no mask, the former president spoke for Biden's character in personal terms.

He called the former vice president "my brother" and declared: "I love Joe Biden, and he will be a great president."

Obama said the president was "jealous of COVID's media coverage" and joked about Trump being obsessed with crowd size.

Obama also dinged Trump on his masculinity, declaring that being a man once meant "taking care of other people," not "strutting and showing off, acting important, bullying people."

Obama won the state of Michigan twice before Trump won it in 2016 by just over 10,000 votes, and he encouraged the crowd to vote, warning them not to be "complacent."

Australian Associated Press