Science in a shifting policy system.

In June, the US Supreme Court overturned a 40-yearold legal principle known as the Chevron doctrine, which deferred to federal agencies on how regulations are interpreted in legal cases when the legislation enacted by Congress is unclear. Striking a blow against this precedent, Supreme Court Chief Justice John Roberts indicated that Chevron was "fundamentally misguided" and that only the nation's courts have the prerogative to interpret the laws they administer. Judges across the United States now anticipate an onslaught of litigation seeking to overturn federal regulatory actions, and many of these lawsuits will turn on scientific evidence that guided those actions. Instead of deferring to the scientific and technical expertise of federal agencies, courts must now independently review the scientific record behind a challenged regulation for its persuasiveness, along with scientific findings produced by the litigating parties. It's too early to fully unpack the impact of overturning Chevron, but the scientific community must step forward to support the crafting of clear and evidence-informed legislation, and the use of scientific evidence in the courts.