Obama rallies young voters for Kamala Harris in swing state Pennsylvania

Former president Barack Obama made a passionate case against Donald Trump and in favour of Vice President Kamala Harris on Thursday during a rally at a Pittsburgh college campus aimed in part at spurring young people to show up for the 5 November election.

Obama has been a vocal supporter of Harris since she ascended to the top of the Democratic ticket after President Joe Biden stepped aside in July following a poor debate performance against Trump, the Republican former president.

Obama, whose White House term ended in 2017, is still popular with his party's base. The rally he headlined at the University of Pittsburgh, held while Harris campaigned in Nevada and Arizona, is the first of several events he plans to do in battleground states in the coming weeks.

"I get it why people are looking to shake things up," Obama said to a crowd of supporters. "I understand people feeling frustrated, feeling 'we can do better.' What I cannot understand is why anybody would think that Donald Trump will shake things up in a way that's good for you, Pennsylvania."

Obama, who argued that Trump only cared about his own ego and money, stressed that Harris was raised in the middle class and believes in American values. "Kamala is as prepared for the job as any nominee for president has ever been."

Obama is not the only former president the Harris campaign intends to deploy on the campaign trail.

Bill Clinton, like Obama a two-term Democratic president, and a former Arkansas governor, will make stops in Georgia on Sunday and Monday before travelling to North Carolina for a bus tour later in the week in an effort to reach rural voters.

Youth are among a critical part of the coalition that the Harris campaign hopes will propel her to victory. But voter registration among young people in 34 states is down compared with four years ago, according to data updated in September from the Centre for Information & Research on Civic Learning and Engagement at Tufts University.

The number of people between the ages of 18 and 29 registered to vote in Pennsylvania in September was 15 percent lower than it was on Election Day in 2020, the centre's data showed.

"I understand why certain younger people feel discouraged and maybe not as passionate about politics or an interest in voting," said rally attendee AJ Herzog, 27, citing the wars in Gaza and Ukraine.

"I think people feel, like, hopeless in certain cases where no matter who they vote for, it's a lot of the same. But I do think there is more opportunity for change with Kamala Harris as president than there is going back to Donald Trump."

Obama's engagement could help get young people motivated in the campaign's final stretch. The former president has sought to serve as a closer for Democratic candidates before, with events for Hillary Clinton in 2016 and for Biden in 2020, especially at the end of the election cycle when early voting had begun, as it has now.

Obama is focused on voters who can put the White House, the House of Representatives and the Senate in Democratic hands, an aide said. The former president has helped raise $US80 million ($NZ131m) for the 2024 presidential campaign.

Obama and his wife, Michelle, gave rousing speeches in support of Harris at the Democratic National Convention in August; the former first lady is expected to campaign further for Harris as well.

Harris was an early supporter of Obama's own 2008 presidential bid, and he has helped her behind the scenes as the party's 2024 standard-bearer, encouraging her to tap talent to bolster her campaign, which she did.

Obama is viewed by some as having helped usher Biden out of the race after Democrats' worries about the 81-year-old leader's age and abilities skyrocketed after his June debate against Trump.

Harris and Trump remain in a close race, and winning Pennsylvania could be key to winning the White House in a battle that will ultimately be determined by the Electoral College.

-Reuters