GEOFF BENNETT: Social media influencers are playing a key role in President Biden's reelection campaign.

It's a way of connecting to younger voters who are harder to reach through traditional advertising.

Here's Laura Barron-Lopez.

HARRY SISSON, Digital Content Creator: All right, everybody.

Joe Biden's about to pull up in the motorcade, so I'm going to get a clip for you guys.

LAURA BARRON-LOPEZ: Twenty-one-year-old Harry Sisson had a special view of President Biden on the night of the State of the Union address, up close and personal from the White House.

HARRY SISSON: President Biden needs four more years in that house.

LAURA BARRON-LOPEZ: And his videos capturing behind-the-scenes moments were broadcast to more than 830,000 followers.

Harry is just one of dozens of social media personalities and influencers that the Biden administration and, more importantly, the Biden campaign is courting, from special invites to White House briefings to State of the Union watch parties, all to get out their message and the vote on platforms like TikTok and Instagram.

HARRY SISSON: I know, in my circle, even just friends, a lot of people are persuaded daily by stuff on TikTok.

They will see a clip of Biden or Trump saying something, and that will change their minds.

LAURA BARRON-LOPEZ: The Biden campaign told "NewsHour" that they aren't currently paying influencers for their content.

HARRY SISSON: I don't think that young people are picking up the phone when a campaign person is making a call.

I don't think the young persons are really going to political rallies unless they're really interested in politics.

Hearing from the candidate in a digital space, not a physical space -- and the reach on TikTok is just remarkable.

It is the best way for candidates to get in touch with young people.

LAURA BARRON-LOPEZ: TikTok and YouTube are the two most popular digital platforms among young people.

Almost a third of young people under the age of 30 get their news regularly from TikTok.

Recent polling shows Biden is struggling with young voters, a key part of the Democratic base, his approval with voters under 30 sitting at 30 percent.

Now they're trying to meet young voters where they are, on the grid.

MAN: But you know who's having a bad day?

Mike Johnson and his House Republican Caucus.

I will tell you why.

LAURA BARRON-LOPEZ: They're hoping that, by partnering with beloved online personalities, the algorithm might work in their favor.

HANNAH MURPHY, Financial Times: They are on social media.

LAURA BARRON-LOPEZ: Hannah Murphy is a reporter at Financial Times covering technology and social media.

HANNAH MURPHY: There's a general wariness, a distrust of traditional media, of politicians themselves.

And this is a way of really reaching out to the people that young people relate to, who look like them, who they trust above all, so finding sort of trusted messengers to speak on your behalf.

REP. NANCY PELOSI (D-CA): Mr. Speaker, I think... LAURA BARRON-LOPEZ: Despite the ongoing scrutiny around TikTok, including legislation that could ban the app if it fails to separate from its Chinese parent company, the Biden campaign is cranking out viral content.

MAN: Trump or Biden?

JOE BIDEN, President of the United States: Are you kidding?

(LAUGHTER) JOE BIDEN: Biden.

LAURA BARRON-LOPEZ: Since their TikTok launch on Super Bowl Sunday, the campaign has been leaning in.

(CHEERING AND APPLAUSE) MAN: Look over here.

WOMAN: Joe.

LAURA BARRON-LOPEZ: Capitalizing on pop culture moments and filming with regular people are all part of the strategy, unvarnished, relatable and genuine.

MAN: The president came to my House to have dinner.

LAURA BARRON-LOPEZ: In 2024, celebrities with millions of followers have arguably less sway than the micro-influencer who has earned the trust of their smaller base.

HANNAH MURPHY: Working with micro- and nano-influencers -- these are folks with thousands of followers, tens of thousands, rather than the millions.

You can really target a particular demographic.

You can geotarget in the battleground state whether the race is really tight.

You could say, I want to find farmers in Wisconsin to put out a particular message.

LAURA BARRON-LOPEZ: Former President Obama revolutionized how once-nascent social media platforms could turn out the vote.

Now there are communications agencies dedicated to partnering campaigns and politicians with influencers as an integral part of their digital strategy.

Veteran Democratic operatives like Teddy Goff see this move as a natural next step.

TEDDY GOFF, Former Obama Campaign Digital Director: You know, I think, especially for young people, but for an increasing number of old people, their perception of the war in Gaza, their perception of LGBTQ rights and all these other issues are being shaped by the experience that they're having on having on TikTok.

And I think it behooves politicians to be there if they want to have a voice in that conversation.

WOMAN: President Joe Biden!

LAURA BARRON-LOPEZ: As long as campaigns remain on social media, there is a lurking threat of disinformation.

But it's a threat that Goff says is best confronted head on.

TEDDY GOFF: I think there's even more danger in not being on it.

I mean, if you're President Biden, disinformation about you can be spreading on TikTok whether you're on it or not.

And so you're going to stand a better chance of combating that disinformation if you're on it.

LAURA BARRON-LOPEZ: I mean, how do you know that what you are putting out there on social media is actually persuading voters or is influencing any voters at all?

TEDDY GOFF: It's really tough to know that.

I think, for that matter, it's really tough to know that with television ads too and with speeches.

You can measure whether people are getting to the end of your video, let's say, or dropping off halfway through your video.

So there are all these proxy metrics for efficacy.

But I think, ultimately, what you -- you can't know that each individual post is effective.

LAURA BARRON-LOPEZ: Former President Trump isn't on some mainstream platforms like TikTok, instead using his own social media platform, TRUTH Social, which he founded after getting kicked off X, formerly known as Twitter, in the aftermath of January 6.

And his campaign points to what they call an organic ecosystem of social media loyalists like Joe Rogan, Libs of TikTok, and Diamond and Silk that have grown over the years, especially on YouTube.

WOMAN: These people are so scared of President Trump.

First off, they know they can't beat him.

LAURA BARRON-LOPEZ: Only the November result will reveal whether the investment in influencers translates to votes.

For the "PBS NewsHour," I'm Laura Barron-Lopez.