California’s authority to set tougher emissions standards dates back to the 1960s when it battled severe smog and created its own air board before the EPA existed. The Clean Air Act of 1970 granted California a unique waiver recognizing its leadership and pollution challenges.

This power enabled California to push cleaner fuels and zero-emission vehicles, influencing other states. The issue is also about environmental justice, as pollution disproportionately harms communities of color.

Big oil companies have lobbied heavily against California’s rules, backing recent political moves to roll back waivers. Meanwhile, tech and EV companies warn this hurts innovation and competitiveness.