On Tuesday night, Taylor Swift made a much-anticipated endorsement – she’s backing Vice President Harris for president. “She fights for the rights and causes I believe need a warrior to champion them,” Swift wrote on Instagram. “I think she is a steady-handed, gifted leader and I believe we can accomplish so much more in this country if we are led by calm and not chaos.”

Last month, Republican presidential nominee Donald Trump reposted an AI-generated image of the pop star wearing an Uncle Sam outfit, in which he accepted her seeming endorsement of his campaign. The post appeared on the politician’s Truth Social network. (He’s since denied he knows anything about the images.)

But Swift wrote that this incident conjured up her fears around AI, and spurred her to share her “actual plans for this election as a voter.” Back when Trump posted the AI image, we took a look at the history of celebrity endorsements and their effects. You can read that story here:

Why celebrity endorsements matter

Celebrity endorsements are as much a thing in politics as they are in consumer products.

“Celebrities draw increased engagement, increased attention, and they increase conversation,” said Ashley Spillane, the author of a new study from Harvard’s Kennedy School on celebrity engagement in politics — focusing on civic participation. “And no matter the political party or the candidate, there is a real hunger to be affiliated with the celebrities that can do that.”

Spillane said her research shows you don’t have to be a star as big as Swift to influence voters.

“Some of the other folks with a smaller base were having just as significant an impact because they have an incredibly engaged base of support as well,” she said. 

There’s a long history of big names throwing their weight behind White House hopefuls. It extends back to 1920 when film stars Mary Pickford and Al Jolson endorsed Warren G. Harding.

Frank Sinatra explained his support of future president Ronald Reagan at a fundraising event in Boston in 1979.

“Why do I support Governor Reagan?” Sinatra said. “Because I think he’s the proper man to be President of the United States. Because it’s so screwed up now, we need someone to straighten it out.”

Oprah Winfrey offered her reasons for backing Barack Obama on The Larry King Show in 2007. “What he stands for, what he has proven he can stand for, what he has shown, was worth me going out on a limb for,” Winfrey said.

A 2008 study from Northwestern University assessed the impact of Winfrey’s endorsement of Obama. It showed the media star was responsible for around one million additional votes for the 44th president.

Celebrity endorsements can be tricky

But other research tells a different story.

For instance, a 2010 report from North Carolina State University found celebrity endorsements by George Clooney and Angelina Jolie did not help political candidates.

And having famous people cheerleading for your political campaign isn’t foolproof.

“It could backfire,” said Wharton School of Business professor of neuroscience, psychology, and marketing Michael Platt, the author of a 2023 study on celebrity endorsement. “Maybe it’s a celebrity that you don’t like or is not aligned with you politically.”

There’s also the potential problem of the celebrity being too famous. Platt calls this the “Vampire Effect.”

“They suck up all our attention, right?” he said. “Which means there’s less attention, less processing, that’s given to the candidate that you might be endorsing.”

The rise of fake AI celebrity endorsements

The rise of social media and deep-fakes created by artificial intelligence, such as those of Swift falsely appearing to endorse Trump, is also an issue.

“There have been manipulated celebrity photographs since the beginning of photography, certainly, but the rampant use of AI and its ubiquity are what is new,” said Douglas Mirell, an entertainment lawyer with the Los Angeles firm Greenberg Glusker who works to curb unauthorized uses of AI. “It is so pervasive and so potentially manipulable, that people can’t tell what’s true and what’s not true. So AI really does create a much more serious threat to the fundamental touchstone of democracy, which is truth-telling.”

Mirell said the impact of AI-generated images, on election results remains to be seen.

“When we’re talking about people like Taylor Swift or Beyoncé, their endorsements would be potentially very important,” he said. “And that’s why I think everyone really needs to be concerned about this issue.”