> Trump says he wants to expand coal, nat gas, etc.. and cheaper prices for those would discourage new solar installations.

This is completely illogical. Increased usage of coal or gas will result in higher prices of those resources, not lower.

In addition, switching back to coal and gas as electrical power sources means lower energy costs. Lower energy costs mean lower manufacturing costs, what will finally result in lower electric car/batteries and solar panels production costs.

Lower electricity costs will also result in lower operational costs of electric cars.