[moey]

Because the Big Three car makers and the National Association of Manufacturers run this state. They said it will "increase costs" and "cost tons of jobs" if a smog law was passed, since they will have to spend more to pass the tests.

[sliverstorm]

You would think those groups would be in favor of regular smog testing, as it accelerates the retirement of old vehicles.

The automakers resisted adding smog equipment (which did increase costs), but that battle is already lost. They already make exclusively 49- and 50-state emissions legal vehicles.

[sukilot]

It is also a PR thing: they don't want the government to admit that the cars are pollutants.