SAN JOSE, Calif. — Silicon Valley ended 2018 somewhere it had never been: embattled.

Lawmakers across the political spectrum say Big Tech, for so long the exalted embodiment of American genius, has too much power. Once seen as a force for making our lives better and our brains smarter, tech is now accused of inflaming, radicalizing, dumbing down and squeezing the masses. Tech company stocks have been pummeled from their highs. Regulation looms. Even tech executives are calling for it.

In the face of such a sustained assault, this might be a good moment for Big Tech to lie low. It could devote some of its mountains of cash — Apple alone has $237 billion in the bank — to genuine good works, and allay widespread fears it wants to control your data and your destiny.

That is not the path the companies are taking.

“The tech companies are not flinching,” said Bob Staedler, a Silicon Valley consultant. “Nothing has hit them on the nose hard enough to tell them to cut back. Instead, they are expanding. They’re going around the country acquiring the best human capital so they can create the next whiz-bang thing.”

There is so much of life that remains undisrupted. The companies are competing to own the cloud — to become, in essence, the internet’s landlord. They have designs on cities: Google made a deal in 2017 to reimagine a chunk of waterfront Toronto from the ground up. Amazon is reworking the definition of community from the inside, as warehouses in rural areas provide the urban middle class with everything they want to stay home all weekend.