Ford Motor also reported a sharp drop in profits in the first three months of the year.
Tariffs on imported parts will have a broad impact because all vehicles use components made abroad.
Republicans, joined by a handful of Democrats, voted to eliminate California’s electric vehicle policy, which had been adopted by 11 other states.
Robyn Denholm, who leads Tesla’s board, said on social media that board members were “highly confident” in Mr. Musk, the company’s chief executive.
The carmaker denied a report that its board had explored finding a successor to Elon Musk. But even if he sticks around, he and the company face big challenges.
General Motors also said its profit in the first three months of the year fell 7 percent from a year earlier.
Trump’s approach risks leaving U.S. automakers isolated and incapable of competing on their own merits as foreign companies bolt ahead.
Donald Trump has set a new standard for egregious and potentially illegal behavior.
The 25 percent levies threaten automakers that are navigating Brexit, a shift to electric vehicles and other obstacles.
Electric vehicles will get even more expensive, but prices for Teslas and some other models may not rise as much as prices for some conventional cars.