Automakers have a strong case when they argue that states should not be allowed to adopt California's tailpipe emissions regulations instead of federal emissions rules.
The federal program is better for business. In the long run, industry experts say, it will lead to improvements in air quality comparable to what California's rules will do.
But history and public opinion are not on the automakers' side. Even though a National Academy of Sciences' panel is studying the states' practices, any proposal to curb their ability to adopt California's rules will be a hard sell.
Automakers are still burdened by the reputation they built decades ago by opposing vehicle emission standards as too costly and technically impractical. Eventually the automakers overcame their own dire forecasts. And in the late 1990s, they produced vehicles that were cleaner than the law required.
A vehicle that meets today's federal standards emits less than 1 percent of the pollutants produced by a vehicle built a generation ago. Nevertheless, seven states have opted out of the federal program while several others are considering such a move. And each state has adopted its own timing, testing and paperwork requirements. That is the evolving regulatory nightmare that the industry says it faces.
Congress should take heed and prevent a hodgepodge of clean air regulations across the country.