Not only does that subsidy take from the pocket of the taxpayer, it also gives an unfair advantage to Nissan.
Imagine you were a small manufacturer or inventor trying to create a vehicle or product EVEN BETTER than the Leaf. The federal government is basically enabling your competition--Nissan--and helping it put YOU out of business.
This is exactly what happened when the feds bailed out the failing GM/Chrysler, etc.
Ford, Toyota and other companies had managed their resources well and did not want bail out monies. But the people who worked for Ford and Toyota ended up PAYING for the bailout of their competition.
If you owned a pizza store and the pizza store three blocks down was failing, would you want the government took a few hundred of your tax dollars to keep your competitor afloat, what would you say?
Finally, I notice there are state incentives in California to buy a Leaf. I would put that into the category of a state's prerogative. If the citizenry of the state has no problem paying for that kind of thing, then let 'em. The federal involvement is what I oppose. Such crony capitalism crushes competition and steals from the taxpayer.