The Harris campaign is hoping the 63-year-old former President - who led the US from 2009 to 2017 - can imbue their White House bid with star power and help fend off the return of Donald Trump.
By midday ahead of the evening rally supporters snaked around the block of the University of Pittsburgh field house, eagerly awaiting entry to see Obama, whose words, Vahabzadeh told AFP, still carry “a lot of weight”.
Valerie Brown, a retired public school teacher, agreed, saying “I love seeing and hearing his articulate self helping to give words that might stimulate some others who are reluctant” to vote for Harris.
Vice-President Harris enjoyed a honeymoon surge in the polls when she replaced President Joe Biden as the Democratic nominee over the summer, capturing the social media zeitgeist and raking in a reported billion dollars in fundraising.
But whether she ultimately can bat back Republican Trump, who is seeking a second term and still maintains a fervent base of support, remains anyone’s guess, with key battleground states like Pennsylvania still vacillating between the candidates in the polls.
Brown’s friend Lisa Harris, also a retired educator and a black woman, said the Democratic ticket represents a vision of the future - while the Republicans offer a return to a dark past.
“We’re not going back,” the 57-year-old said. “People died for us to have the right to vote, for us to have the rights to our bodies, to our minds and our souls.”
I loved him as a kid
That sentiment strikes a chord on the campus of the University of Pittsburgh, where 20-year-old Tia Douglas also lined up with friends for a glimpse of Obama - who was first elected when she was not even yet primary-age.
“It’s super historic that Obama, like, our first president of colour, is campaigning again for our first woman of colour vice-president,” she said, sporting the now-cult camouflage Harris campaign hat.
“To see them join forces for the greater good, I think is really amazing,” Douglas said. “I grew up with Obama as a president, but we weren’t really part of that political history, I was too young.
“It’s cool to see him back on the ground” and setting up a vision of Harris as his political successor, she said.
Cool enough to wait for hours in an ageing university gymnasium for the marquee speaker, whose “Yes We Can” slogan from 2008 was repurposed as “Yes She Can” and emblazoned on both homemade posters and an electric scoreboard in the field house.
Douglas’ friend Julia Palchikoff, a 20-year-old journalism major, said maturing in the Trump era made her appreciate Obama even more.
“Being in a swing state in an election like this, it’s just a historical moment, and I feel like I have to do my part,” said the Alaska native who moved to Pennsylvania for school.
“When I heard Obama was coming here, I was, like, I loved him as a kid - and Kamala, honestly, it just feels like we’re on the precipice of something really great.