I wouldn't be surprised if tracking happened. Pretty much every new car comes with GPS now, and it could be made to self-report. People would fight it (and I might agree with them) but I think it could happen.
I don't see taxing electricity at the charger as being viable, because it's too decentralized. You can tax gasoline because it's distributed by relatively few places. You can charge a car off a normal 240V outlet (or 120V if you don't mind it being slow) so it'll be way too easy to dodge.
Tracking mileage and assigning to the state of registration might not be too bad. It won't be fully accurate, but the inaccuracies will balance out to an extent. Gas already suffers from this at a smaller level, since you can buy gas in one state and then drive a substantial distance in another state.
The fact that trucks are the ones doing all the damage is a big wrench in the works. Maybe the proper solution would be paying some by taxing truck mileage and making up the rest out of general taxes.