This week, more than 2,000 Google employees walked out of work to protest President Trump’s immigration ban. Far from disciplining them for leaving their desks, CEO Sundar Pichai and co-founder Sergey Brin treated workers to impassioned speeches of support.

"Proud, moved, and touched to be at a company that boldly stands for its people," Googler Sam Tse tweeted. The hashtag #GooglersUnite trended.

While Pichai and Brin were no doubt speaking from personal conviction—Brin's family fled the former Soviet Union when he was a boy—they also had little choice but to back their employees. Trump's directive cut to the heart of Silicon Valley's treasured values of globalism and openness, values widely embraced by the workers themselves. And in Silicon Valley, where companies' success depends so deeply on their rosters of intellectual talent, it's the workers who have the leverage to force their bosses to respond when the president threatens those values.

The power of that pressure was on full display yesterday when Uber CEO Travis Kalanick stepped down from Trump's economic advisory council. "There are many ways we will continue to advocate for just change on immigration, but staying on the council was going to get in the way of that," Kalanick wrote in an email to employees. His decision came after the #DeleteUber hashtag campaign went viral over the company's response to Trump's ban. But according to a New York Times report, the real arm-twisting may have come from employees furious that Kalanick's membership on the council looked like a company endorsement of the administration.

Only two weeks into Trump's presidency, it's clear Kalanick won't be the last CEO to face this kind of criticism not just from outsiders but from inside their companies themselves. Silicon Valley's workforce is heavily liberal and deeply committed to the notion of itself as a meritocracy—a place where people succeed on the quality of their ideas, not where they're from. Given the seller's market for their talent, tech workers have real power to influence their bosses' postures toward the president. If their CEO doesn't stand up aggressively to Trump, they can always go work for a CEO who does.

So Many Choices

It's an old Silicon Valley lament that the tech industry faces a severe talent shortage, but it remains true. Jobs in computing are growing at twice the national rate of other occupations—far faster than the country is turning out qualified workers to fill them.

"Our students are regularly getting dozens of offers, and they are stressed out by having to choose among so many options," says Andrew Moore, dean of Carnegie Mellon University’s School of Computer Science.

'Our students are regularly getting dozens of offers, and they are stressed out by having to choose among so many options.'

At the most mercenary level, the competition is fierce because talented employees make tech companies lots of money. Facebook employees generate $1.9 million in revenue annually per person, while the median compensation is about $150,000. "An employee’s return on investment is higher than drug dealing," says John Sullivan, a human resources strategist and management professor at San Francisco State University. "It’s not the buildings, the location, or the equipment that make these tech firms excel at serial innovation. Instead, it’s the quality and capabilities of the people that they attract and retain." The competition gets even fiercer in more specialized fields like machine learning and artificial intelligence, where the best command salaries more akin to professional athletes than office workers.

With talent so precious and scarce, tech companies have little choice but to take their workers' politics seriously. "In Silicon Valley, the pressure for firms to act 100 percent politically correct is constant and powerful," says Sullivan. "The turnover rate is already so high at firms like Google, that it makes no sense to do anything that might anger even a small portion of your workforce." It makes sense, then, that techies would scrutinize their prospective employers based on whether those companies and their leaders exhibit values that align with their own worldviews. And these days, those views are likely to be anti-Trump.

"The tech community in general contains a very high proportion of recent migrants or children of migrants,” says Yoshua Bengio, director of the University of Montreal’s Montreal Institute for Learning Algorithms, a hub for AI talent. "With near unanimity against the Trump immigration ban among all the people in that community, it is not surprising to see companies making public moves against this ban." For some, even those public displays are not enough. Bengio says he knows top researchers who are now looking for jobs outside of the US.