Silicon Valley may be a bastion of liberals, but the threat of a Donald Trump presidency had some of technology’s biggest names meeting behind closed doors with members of the Republican elite.

Apple CEO Tim Cook, Google co-founder and Alphabet CEO Larry Page and billionaire Facebook investor Sean Parker met with GOP officials last weekend to talk about stopping the mogul-turned-reality-star from becoming president, according to a report by The Huffington Post, citing people familiar with the event.

“There was much unhappiness about his emergence, a good deal of talk, some of it insightful and thoughtful, about why he’s done so well, and many expressions of hope that he would be defeated,” Weekly Standard editor Bill Kristol wrote in an emailed report that the Huffington Post obtained and that borrowed from unlikely source material — Karl Marx’s “The Communist Manifesto.”

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“The key task now … is less to understand Trump than to stop him,” Kristol continued. “In general, there’s a little too much hand-wringing, brow-furrowing, and fatalism out there and not quite enough resolving to save the party from nominating or the country electing someone who simply shouldn’t be president.”

The off-the-record meeting happened as part of the neoconservative American Enterprise Institute’s annual World Forum, a famously secretive summit on a private island resort off the coast of Georgia.

Attendees included Republican strategist Karl Rove, Senate Majority Leader Mitch McConnell, New York Times publisher Arthur Sulzberger and Arkansas Sen. Tom Cotton, who also had a tense debate with Apple’s Cook over the company’s fight with the FBI over a terrorist’s locked iPhone.

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But the meeting’s highlight was Rove presenting focus group findings about Trump, which indicated that the frontrunner’s biggest weakness is that voters have difficulty envisioning him as “presidential” or a role model for children.

Much of the conversation around Trump centered on how his momentum reached the point where he became the presumptive nominee, rather than how to stop him, the report said, citing sources familiar with the meeting.

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Apple, Alphabet, Facebook, and the New York Times didn’t respond to TheWrap’s messages seeking comment. Representatives for Rove, McConnell and Cotton also didn’t immediately respond to requests for comment.

For the record: An earlier version of this story quoted Huffington Post as reporting Tesla CEO Elon Musk attended the meeting, and Tesla didn’t respond to TheWrap’s message seeking comment. In a subsequent tweet, Musk denied the meeting was secret and said his involvement was related to Mars and sustainable energy, not Trump.