Oil refineries in particular are interesting because the sources for the blend of gasoline California requires[0] are either in CA itself or are few and far away. This means that gasoline prices are susceptible to greater supply shocks and so on. Many US regulations follow from California exercising its large market to induce companies to change their policies (electronic one-click cancel, CCPA, No Surprises in healthcare billing) but this one hasn't quite had the same effect.

One can hope that most Californians switch to BEVs from ICE vehicles before this becomes more of a constraint.

Gasoline usage externalities are poorly priced-in so the resulting increase in cost of gasoline here is probably overall a good thing. If we had appropriate carbon/sulphur/etc pricing on the outputs, I think it would be less justifiable since then the externalities would be priced in.

0: https://www.eia.gov/todayinenergy/detail.php?id=65184