Some said they worried that California’s planned ban on gas-powered vehicles would raise the price of cars. Another cited “intense and misleading lobbying” by the oil industry.
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.
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.
The 25 percent levies threaten automakers that are navigating Brexit, a shift to electric vehicles and other obstacles.
Elon Musk’s alliance with President Trump has prompted Democratic lawmakers to propose stripping Tesla of its ability to sell its cars directly to consumers.
America needs to figure out how to dominate the industries of the future. Call me a “Waymo Democrat.”