Investor Bill Ackman, David Sacks' PAC donated to RFK Jr.'s presidential campaign

Billionaire hedge fund chief Bill Ackman donated $3,300 in the second quarter to Democrat and anti-vaccine presidential candidate Robert F. Kennedy Jr.'s campaign during the second quarter, according to a Federal Election Commission filing.

Ackman's donation came just days after he sided, in a tweet, with Kennedy's broadly debunked skepticism about vaccines.

Ackman, the CEO of Pershing Square Capital, explained to CNBC days later: "I listened to RFK on several podcasts and a town hall and thought he raised important issues about vaccines and other issues that were worth learning more about." When asked at the time, he didn't say whether he had donated to Kennedy's campaign.

Ackman is one of several prominent business leaders who donated to Kennedy's campaign in the second quarter. The Purple Good Government PAC, a committee that's been largely funded by investor and Elon Musk ally David Sacks, donated $6,600 to the campaign.

Ken Fisher, the founder and executive chairman of Fisher Investments, donated $6,600 to the campaign, according to the filing.

Veteran Wall Street executive Omeed Malik also donated $6,600 to the Kennedy campaign, the filing says. Malik is hosting a fundraiser for Kennedy in the Hamptons this month. Brett Messing, a partner at Anthony Scaramucci's SkyBridge Capital, also donated the campaign, according to the filing.

A donor named Eric Clapton, identified as a musician with an address in England, donated $5,000 to Kennedy's campaign.

It wasn't immediately clear if that donor was the same person as the legendary English guitarist Eric Clapton, who has a long history of airing controversial views and released an anti-vaccine and Covid lockdown protest song during the Covid pandemic. The filing notes next to the donation: "refund in subsequent period." Federal law prohibits donations to U.S. campaigns from foreign nationals.

The most an individual can give toward helping a candidate in either a primary or general election season within an election cycle is $3,300. A $6,600 donation can be split between the primary and general election accounts.

The second quarter spans from April 1 until June 30.

Ackman's spokesman declined to comment. A spokeswoman for Sacks did not return a request for comment. Fisher did not return a request for comment. A spokeswoman for Clapton did not return a request for comment.

Sacks co-hosted an event in June with fellow tech leader Chamath Palihapitiya that raised approximately $500,000. The Kennedy campaign finished raising over $6 million, with over $4 million on hand. Neither Sacks nor Palihapitiya are listed on the campaign fundraising filing as having contributed toward Kennedy's run.

President Joe Biden, Kennedy's rival, raised over $72 million in the second quarter.

A June Quinnipiac poll shows Biden with 70 % support among Democrats and Democratic-leaning voters, while Kennedy has 17% among those same groups.

CNBC's Kevin Breuninger contributed to this article.