Switching a significant portion of the national car fleet over to electric power will not be as easy as making the cars. Just manufacturing those millions of electric vehicles is a job in itself. The infrastructure needed to support them is also huge.
If everyone wanted to charge their vehicles at the same time no city's power grid could handle it. On trickle charge where everybody draws a little power at different times it could be possible. Arranging systems to support burst charges by everybody when they come home after the commute is another story. Also lacking is a national infrastructure of rapid recharge stations or battery swapping programs.
There are also political and economical issues. For example, if everybody wants to plug in at their employer's parking lot, who pays and how do you know how much? The infrastructure we have now, gas stations, makes it clear who pays and when. But if people can start plugging in anywhere there is an outlet that will change.
These are questions that we are going to be confronted with soon, judging by the steady increase in assembly lines turning out plug in hybrid vehicles and pure electric vehicles. The sooner we start to think about them and resolve them as a nation the easier the adoption of electric vehicles will be.