[biblewonk]

"Federal law and common sense prohibit each state from developing its own fuel economy standards,"

Surely no proper conservative would be ok with this. A conservative should applaud California for doing something it's own way instead of the way the Federal Gmt wants.

[newgeezer]

For many years, CA had its own emissions standards, and auto manufacturers responded by making 49-state-equipped cars and CA-equipped cars. Of course, they could have (and I suspect, in some cases, did) respond by selling the cleaner CA cars everywhere. But, for the most part at least, the mfrs. knew consumers in the other 49 states would not be happy driving the slower and/or less-efficient CA-equipped cars, especially if the competition was selling faster, more-efficient cars.

That said, I believe individual states should be free to impose whatever emissions standards they wish on new, used, imported, or whatever cars they want at the peril of their voters. (For example,) Let North Dakota impose a hodge-podge of emissions standards, and see how many auto mfrs. simply decide not to sell cars to North Dakotans. Or, see how happy North Dakotans are in paying 20% more than South Dakotans for the same model.