Section 209(a) of the Clean Air Act generally preempts States from adopting emission standards for new motor vehicles. 42 U.S.C. § 7543(a). But under Section 209(b) of that Act, EPA may grant California and only California-a waiver from federal preemption to set its own vehicle-emission standards. Before granting a preemption waiver, EPA must find that California "need[s]" its own emission standards "to meet compelling and extraordinary conditions." Id. § 7543(b)(1)(B).

In 2022, EPA granted California a waiver to set its own standards for greenhouse-gas emissions and to adopt a zero-emission-vehicle mandate, both expressly intended to address global climate change by reducing California vehicles' consumption of liquid fuel. Fuel producers challenged EPA's waiver as contrary to the text of Section 209(b). The D.C. Circuit rejected the challenge without reaching the merits, concluding that fuel producers' injuries were not redressable because they had not established that vacating EP A's waiver would have any effect on automakers.

The questions presented are:

1. Whether a party may establish the redressability component of Article III standing by relying on the coercive and predictable effects of regulation on third parties.

2. Whether EPA's preemption waiver for California's greenhouse-gas emission standards and zero-emission- vehicle mandate is unlawful.

The question presented is: When a noncitizen's voluntary-departure period ends on a weekend or public holiday, is a motion to reopen filed the next business day sufficient to avoid the penalties for failure to depart?

The Supreme Court held: Under §1229c(b)(2), a voluntary-departure deadline that falls on a weekend or legal holiday extends to the next business day.

Whether a proceeding under 26 U.S.C. 6330 for a pre-deprivation determination about a levy proposed by the Internal Revenue Service to collect unpaid taxes becomes moot when there is no longer a live dispute over the proposed levy that gave rise to the proceeding.