On July 10, A-list actor George Clooney asked a struggling Joe Biden to withdraw from the presidential race with Donald Trump and make way for a fresh face. When news broke Sunday that the incumbent had dropped out and endorsed his vice president, Kamala Harris, a host of Hollywood luminaries from actors Robert De Niro to Jamie Lee Curtis expressed their immediate support for the switch.

Curtis, star of horror classics like "Halloween," took to Instagram soon after the announcement to heartily endorse Harris — a former attorney general of California and US senator who has yet to be formally nominated by the Democratic Party.

"She is a fierce advocate for women's rights and people of color and her message is one of HOPE and UNITY for America at her time of great national divide," wrote Curtis in a post that had nearly 250,000 likes on Monday morning.

Pop stars fuel memes, music set to drive youth vote

A day after Harris was endorsed by Biden, she was first welcomed by cheering campaign staff in Delaware to Beyonce's hit song "Freedom" — featuring rapper Kendrick Lamar, it appeared on the 2016 Beyonce album, "Lemonade."

As reported on CNN, the pop icon had been quick to give Harris' team permission to use the song throughout the presidential campaign, though Beyonce has yet to officially endorse the likely Democratic candidate.

But the celebrity endorsement with perhaps the most impact came from across the pond, when British singer Charli XCX pronounced on X that "Kamala IS brat" — a reference to the singer's chart-topping album, "Brat." More than 50 million people have since viewed the post.

Making the link between Harris and Charli XCX's irreverent brand of pop music is set to strike a chord with Gen Zs, who could swing the election in Harris' favor.

The presidential hopeful's campaign team were quick to change its profile X to lime green, the color of the "Brat" record, and to use the same font to spell out "kamala hq."

Charlie XCX' music features among the endless TikTok and social media memes that celebrate a dancing and laughing Harris, a theme that complements her growing affinity with younger voters, as noted by social media personality Ed Krassenstein on X (formerly Twitter).

Hollywood unites quickly around Harris

Elizabeth Wagmeister, a CNN entertainment correspondent, wrote on X that the sudden celebrity support for Harris was unprecedented this election cycle.

"Hollywood has galvanized around Kamala Harris more in the past 3 hours than it did this entire election cycle for Biden," she wrote on Sunday evening.

De Niro said in a statement that it was essential that Biden stepped aside "because there is nothing more important for our country than defeating Donald Trump at the ballot box."

"With respect, admiration, and affection, thank you Mr. President!" the Oscar-winning actor added.

Hollywood icons like Barbra Streisand were also quick to respond to the news, with the singer commenting on X about Biden's "significant achievements in his 4 year term," adding that Americans should be "grateful for his upholding of our democracy."

Cardi B says Biden should have 'passed the torch' sooner

"Ahahahaha lets gooooo i told yalll kamala was supposed to be the 2024 candidate," wrote rapper Cardi B on X, pointing out she had singled out Harris as Biden's replacement weeks before.

"It was very selfish of Biden and the whole Democratic Party," the singer said in a video of her wish that Harris had received the nomination from the start of the reelection campaign.

"I feel they should have passed the torch to Kamala," Cardi B added. "This was the perfect moment for her. This would have been her perfect time to shine."

There remains much expectation that pop music's brightest star, Taylor Swift, will come out and endorse Harris, having pledged support for the Biden and Harris Democratic ticket during the 2020 election.

Social media accounts like "Swifties for Harris" sprung up only hours after the announcement that the vice president would likely lead the Democrats in November. The unofficial Swift fan page on X aims to "mobilize Taylor Swift fans to help get Democratic candidates elected up & down the ballot!"

Obama yet to endorse Harris

Barack Obama, who is best known for his work on Netflix and as a podcaster since his presidency ended in 2017, praised his former vice president for dropping out of the race.

"Joe Biden has been one of America's most consequential presidents, as well as a dear friend and partner to me," he wrote on X. "Today, we've also been reminded — again — that he's a patriot of the highest order."

But Obama has yet to endorse Harris, unlike many top Democratic lawmakers and a slew of pop stars and Hollywood celebrities.

Meanwhile, Trump-supporting celebrities like actor and comedian Russell Brand took to social media to argue that Harris was not an effective public speaker, besides commenting on her laugh. Republicans have started to refer to the potential candidate as "cackling Kamala."

It remains to be seen who will get the last laugh, though, when the US presidential election takes place on November 5.