One inherent
problem with pure-
electric cars is that it completely
ignores the fact that electricity usually isn't very
clean to
produce.
In fact, the
argument could easily be
made that a gas-powered
kinetic energy generator (i.e. the
engine in an
automobile) is a hell of a lot more
efficient than having a gas-powered
electrical energy generator shove electrical energy into a
battery and having that power an electric motor.
Hybrid cars are definitely much more efficient than either method, in any case, as evidenced by the current hybrid cars (which are basically normal petrolmobiles with a generator-motor pair instead of a normal engine) getting ungodly fuel efficiency.
Of course, pure-electric cars are probably overall more efficient than pure-gasoline ones, but they're certainly not pollution-free - last I checked, most places in the country still rely on fossil fuel electricity generation (solar and wind are too expensive, and nuclear is too untrusted).