Why would it not be legal to import electric cars? The cumulatively most sold electric vehicle in the US, the Nissan Leaf, started off manufacturing in Japan only, and the initial batch in the US was all imported. The just launched BWM i3 and i8 are both imported, as well as the VW e-golf and a number of others.
And not be legal to drive? By the end of 2015 we will be at nearly 400k electric vehicles sold in just the US [1]. A faster adoption rate than hybrid vehicles [2].
[1] - https://en.wikipedia.org/wiki/Plug-in_electric_vehicles_in_t...
[2] - https://en.wikipedia.org/wiki/Plug-in_electric_vehicles_in_t...