“That was a nice way of saying 86 percent of them didn’t think so,” he said.

Others disagree that consumers think of zero emissions cars as broccoli. “That would be interesting if it was true,” said Mary Nichols, the chairwoman of the Air Resources Board, a California agency that Gov. Jerry Brown has charged with developing policies to spur electric car sales. Ms. Nichols said she believed that consumers wanted these cars and that they had been dissuaded in part by unenthusiastic dealers and “horror story” sales experiences.

California has 150,000 electric cars, but that figure needs to grow tenfold in the next decade, she said, or the state will not be able to meet its environmental goals. Without the cars, “simply put, we can’t make it,” she added.

Industry insiders and those who follow the business closely say that dealers may also be worrying about their bottom lines. They assert that electric vehicles do not offer dealers the profits that gas-powered cars do. They take more time to sell because of the explaining required, which hurts overall sales and commissions. Electric vehicles also may require less maintenance, undermining the biggest source of dealer profits: their service departments.

Dealers’ caution, whatever their reasons, has created a “reality check to the idealism,” said Eric Cahill, who recently completed a dissertation on electric car sales for the Institute of Transportation Studies at the University of California, Davis. Retailers are a “bottleneck,” his research shows. They may hold the key to growing the niche, but dealers “may have very good reasons for steering a potential buyer away from an E.V.”