A pair of celebrities with appeal to different factions of younger Americans added to Kamala Harris’ celebrity support, as both the vice president and Donald Trump vie to turn out first-time voters in the final weeks of an exceedingly tight election race.

Pop star Billie Eilish posted a video alongside her brother on Instagram encouraging her followers to register to vote, with the siblings revealing that they plan to cast their ballots for Harris. Podcaster Joe Rogan applauded Harris’ political team for their messaging strategy and her recent debate performance without directly endorsing her candidacy.

The celebrities’ comments — broadcast after Taylor Swift’s endorsement of Harris following last week’s debate — could prove to be a significant factor in turning out younger voters heavily courted by both campaigns. Rogan’s compliments, while not a direct endorsement, offered implicit support for Harris. That’s a drawback for the Trump campaign’s strategy to target younger men, who are a key part of Rogan’s listener base.

“They did an amazing job, from the moment Biden drops out, forcing Biden to drop out,” Rogan said of the Harris team in an episode recorded on Sept. 11 that aired Monday. “Whatever they’re doing, whoever’s writing those speeches” and coaching her, “she’s nailing it.”

Rogan, a controversial figure for spreading misinformation and past racist comments, has been openly critical of Trump. He’s demonstrated mixed political loyalties in the past, having endorsed Bernie Sanders in the 2020 race while saying then that he would also favor Trump over Biden, and previously expressing support for independent Robert F. Kennedy, Jr. in the 2024 cycle.

The Joe Rogan Experience is the No. 1 podcast on Spotify Technology SA by unique listeners and overall follower counts, and No. 5 in an Apple Podcasts ranking that considers audience size, engagement, and completion of episodes. Eilish and her brother, who has written and produced many of her songs, have a combined following of 123 million on the Meta Platforms Inc. app.

“We are voting for Kamala Harris and Tim Walz, because they are fighting to protect our reproductive freedom, our planet and our democracy,” Billie Eilish, 22, said in the video. “Vote like your life depends on it, because it does.”

The Harris campaign’s Instagram account commented on the post, making a reference to one of Eilish’s hit songs. “Birds of a feather,” they wrote, with a heart emoji.

Some of the biggest names in Democratic-leaning Hollywood have already endorsed Harris, including Swift and media mogul Oprah Winfrey, who is campaigning with Harris this week. Economists Craig Garthwaite and Timothy Moore, assessing the impact of Winfrey’s support for Barack Obama in his first run for president in 2008, found that her endorsement helped add about 1 million votes toward his victory.

While celebrity endorsements are rarely seen as a game changer, polling that shows Harris and Trump essentially tied underscores how much get-out-the-vote efforts could play an out-sized role. Several celebrities encouraged their fans to register to vote on Tuesday, which marked National Voter Registration Day in the US.