File photo. / Reuters

Washington, United States

Kamala Harris has Bruce Springsteen and Eminem. Donald Trump has the world's richest man. But will it make any difference on Election Day?

Celebrity endorsements do little to sway voter opinion, experts say, and polls show only a sliver of the electorate have yet to make up their mind before the November 5 vote.

But big names appearing at campaign events help to grab headlines and boost enthusiasm among key groups, which could spur higher turnout or motivate more early voting -- as millions have already done.

With two weeks to go, "your real goal right now has to be to get your audience, your voters to show up," Megan Duncan, a communications professor at Virginia Tech, told AFP.

In an election expected to be decided by razor thin margins in a handful of states, any marginal lift could prove decisive.

On Tuesday, Harris got the endorsement of rapper and Detroit icon Eminem at a rally in the city. Also attending was former president Barack Obama, a superstar in the Democratic Party who rapped the opening segments of Eminem's famous hit "Lose Yourself" to cheers from the crowd.

Duncan said celebrities would be used more by campaigns in the final two weeks to tap into a localized "sense of identity," with appearances becoming "more targeted" to specific cities.

Popstar Lizzo joined Harris last weekend for an event to mark the first day of early voting in the "About Damn Time" singer's home city of Detroit, while R&B star Usher appeared with the vice president in Atlanta, where he launched his career.

Democrats hope that the potent presence of Obama, America's first Black US president, and his popular wife, former first lady Michelle Obama, will shore up support among African American voters, particularly men, in key cities.

The former president is also set to hold multiple events with rocker Bruce Springsteen in the coming days, with Harris joining them in Atlanta on Thursday, her campaign said.

Superstar Taylor Swift endorsed Harris minutes after her first and only debate against Trump, in early September, timing which Duncan called "very strategic... to have the most impact."

Team Trump

Trump has relatively few celebs in his corner, but a few power hitters are nonetheless working to push him over the finish line.

Most notably is the world's richest person, Elon Musk, who has donated at least $75 million to efforts at electing Trump and other Republicans.

The SpaceX and Tesla boss has also used his influential platform on X, which he rebranded from Twitter after buying it, to boost Trump-aligned and often false narratives about immigration and other hot-button issues.

In recent days, he has campaigned for Trump in Pennsylvania, telling voters there that the key swing state could decide the "fate of Western civilization."

But the eccentric billionaire has also courted controversy, including by launching a legally dubious $1 million daily sweepstakes that only registered voters in swing states can win.

While Musk's support could lift enthusiasm among some who view him favorably, particularly young men, it also risks alienating moderate voters weary from almost a decade of Trump's norm-breaking.

The Trump campaign's push to expand support among young men has received a boost from Dana White, the CEO of the Ultimate Fighting Championship (UFC), who spoke at the Republican National Convention in July and recently on ex-NFL star Robert Griffin III's podcast.

Trump's backers also include several financial personalities with large social media followings, including David Sacks and Bill Ackman, and a few prominent Hollywood actors such as Jon Voight and Dennis Quaid.

But aside from Kid Rock and country singer Lee Greenwood, who frequently performs his patriotic anthem "God Bless the USA" at rallies, Trump has few star musicians to lean on in the final two weeks.

The Republican instead uses on an oft-repeated playlist, which includes the Village People's 1978 hits "Y.M.C.A." and "Macho Man."

Trump's campaign has seen several musicians or their estates threaten legal action against unapproved uses of their songs.

The most recent action came last week, after the 78-year-old played Leonard Cohen's "Hallelujah," as performed by Rufus Wainwright, at an event in Pennsylvania.