When Jennifer Trebb first pulled into her driveway two years ago with her sleek Tesla Model Y, it was — as she put it — “kind of like a ‘Back to the Future’ moment.”

She was helping the environment, she said, but driving a Tesla also had cachet. “It was definitely a little bit of a cool moment to have something that was innovative and different,” she said.

But Ms. Trebb recently made a U-turn, joining the ranks of Tesla owners in the United States and overseas — some well known, including the singer Sheryl Crow — who are selling their vehicles because the values and politics of the company’s billionaire chief executive, Elon Musk, are alienating them, they say. His role in the Trump administration, exerting his power over the federal government, has exacerbated that tension.

The buyer’s remorse is playing out at a volatile moment for Tesla, as stocks dropped by double digits in the last week, wiping out most of a post-election surge for Mr. Musk’s company. A recent report showed plummeting sales in Europe, and the company faces increased competition from other E.V. makers eating away at its market share. Recent protests outside Tesla showrooms in the United States and some notable cases of vehicle owners being harassed have also made headlines.

Ms. Trebb, 54, a family therapist and a Democrat, said she had decided to trade in her Tesla for a gas-powered Mercedes, accepting $32,000 of the Tesla’s original $55,880 value, despite having only 10,000 miles on it. Her decision, she said, was cemented during a recent trip to the supermarket.

“Two weeks ago, I was called a Nazi,” she said, “in the parking lot at Kroger,” adding an expletive. “I came home and told my husband, ‘That’s it. I’m done.’”