President Donald Trump's Silicon Valley donors traveled to a secret location in Palo Alto, California, on Tuesday to attend a fundraiser for the president where tickets cost as much as $100,000 a couple, according to a new report from The Wall Street Journal.

Attendees weren't told in advance where the event would be or who would be hosting. Instead, they were asked to meet at a remote location before being shuttled to the host's house — reported to be that of the Sun Microsystems cofounder Scott McNealy.

Trump has made few inroads in Silicon Valley in the past, and the industry has a reputation as left-leaning. For this reason, fundraising events aren't always welcome in the area.

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Silicon Valley hosted a secretive fundraiser for President Donald Trump in Palo Alto, California, on Tuesday, with tickets costing as much as $100,000 a couple.

The Wall Street Journal reported that attendees weren't told in advance where the event would be or who would be hosting, in part over worries that protesters might turn up en masse.

Instead, attendees were asked to meet at a remote location before being shuttled to the host's house. Campaign aides and advisers declined to disclose the location and its host, citing privacy and security concerns, The Journal said.

It turned out that Scott McNealy, the cofounder and former CEO of Sun Microsystems, was hosting the fundraiser at his Palo Alto home. Crowds of protesters caught wind of the event and duly gathered nearby along with, apparently, a giant balloon depicting Trump as a baby.

—Evelyn Jean Pine (@evypine) September 18, 2019

The secrecy was indicative of Trump's status in Silicon Valley. The president has made few inroads in the tech industry, and the wider industry has a reputation as left-leaning.

In the 2016 election, nearly 99% of the political donations from Silicon Valley went to Hilary Clinton while just 1% went to Trump, for example.

This year, several high-profile Silicon Valley figures have already made donations to Democratic presidential hopefuls.

According to ABC, the Democratic presidential candidate Pete Buttigieg has racked up donations from Alphabet's chairman, Eric Schmidt; DoorDash CEO Tony Xu; and Pinterest's founder, Ben Silbermann. Sen. Kamala Harris, another Democratic challenger, has received cash from LinkedIn's founder, Reid Hoffman; Salesforce's chairman, Marc Benioff; and Impossible Foods' president, Dennis Woodside.

Read more: People are threatening to quit Equinox and SoulCycle following a report that the chairman of the trendy fitness brands plans to host a Trump fundraiser

Silicon Valley's left-leaning tendencies might explain why Republican fundraisers aren't always welcome in the area.

Three years ago, Intel's then-CEO, Brian Krzanich, was forced to cancel an event for Trump at his Atherton, California, home hours after the plan went public because it caused an uproar among employees, according to The Journal.

The developer Stephen Ross faced an even bigger backlash this summer after he hosted a fundraiser for Trump at his Hamptons mansion; hundreds of people took to social media to boycott the companies he invested in.