If there is anyplace Tesla should be thriving, it’s Norway. Electric vehicles account for more than 90 percent of new car sales in the Scandinavian country, and buyers here are among the most sophisticated in the world when it comes to understanding the nuances of batteries, charging and range.

So it hardly bodes well for Tesla that its sales in Norway have declined more than 12 percent so far this year. Sales for the first three months of the year were even worse in Denmark, France, the Netherlands and Sweden. Analysts expect the downward trend to be reflected when the company reports its worldwide sales for the first quarter on Wednesday.

Wall Street analysts expect Tesla deliveries worldwide to have declined sharply from a year earlier, reflecting several serious problems, not least a consumer backlash against the prominent role that Elon Musk, the company’s chief executive, is playing in the Trump administration.

Geir Rognlien Elgvin, an urban planner with the City of Oslo, bought his first Tesla in 2013, months after they were introduced in Norway. He has toured the company’s battery Gigafactory in Nevada. He met Mr. Musk when the executive was still mostly known for wanting to address climate change with electric cars and his rocket company, SpaceX.

But as Mr. Musk drifted to right-wing politics, Mr. Elgvin’s enthusiasm waned. And he grew concerned about the company’s data security policy.