"He designs everything at Apple," said Mossberg. "If we watch how this immigration thing goes, not just this executive order, but if it broadens out, that's a big problem for tech."
The CEOs of big tech companies must walk a "very fine line," said Megan Quinn, a venture capital partner with Spark Capital.
They must work with government — which in some cases is also a customer — and serve their employees at companies where nearly 40 percent are foreign-born, while appeasing shareholders and customers, she said.
"We have seen CEOs take different paths to influence, but it's certainly top of mind here in Silicon Valley," said Quinn.
The U.S. has always been open to immigration — sometimes more and sometimes less — and historical rhetoric from Trump advisor Steve Bannon and others suggests the country might be headed for a clampdown on immigration, said Mossberg.
"I expect the tech industry to be very disturbed by that," he said.
Beyond immigration, Apple in particular has planted a flag in the ground regarding privacy and security of the iPhone, said Mossberg.
"That fight is much harder under President Trump," he said.
If customers in the U.S. and abroad see Apple as less protective of privacy, that will be a problem for the company, he said.