Conservative justices on the Supreme Court engaged in a rigorous debate with the Biden administration on Wednesday, questioning the extent to which judges should interpret ambiguous laws passed by Congress instead of federal agencies. This pivotal ruling could potentially grant courts, including the Supreme Court itself, greater authority to strike down regulations on various policy areas, such as health care, the environment, and immigration, that fall under the purview of federal agencies. Such a decision would ultimately limit the power of the executive branch and make it more challenging for President Joe Biden and future presidents to defend their regulatory agendas against legal challenges.

Justice Brett Kavanaugh, a vocal critic of the Chevron doctrine under scrutiny, argued that it is the historical role of the judiciary under the Constitution to maintain a clear distinction between the legislative and executive branches, preventing the executive from operating as a "king." Echoing this sentiment, Justice Neil Gorsuch challenged the administration on when courts should defer to federal agency interpretations of laws that delegate broad authority. Justice Ketanji Brown Jackson, however, warned against the potential danger of judges becoming "uber-legislators" if the court rules in favor of conservatives.

Central to the debate is the 40-year-old Chevron doctrine, established during a legal dispute between the oil industry and environmentalists during the Reagan era. This doctrine stipulates that when a statute is ambiguous, judges must uphold regulations crafted by federal agencies based on these agencies' "reasonable" interpretation of the statute. The purpose of this doctrine was to prevent judges from overriding policy decisions or technical expertise of agencies, with proponents also arguing that agencies require flexibility to act in situations where Congress cannot legislate for every possibility.

Both Democrats and Republicans have utilized the Chevron doctrine to defend their respective agendas over the years. Studies have shown that agencies are more successful under this standard, as compared to when courts review their actions without deference. However, conservative legal thinkers have consistently pushed for the overturning of Chevron, asserting that it undermines the ability of judges to determine the law in a fundamental violation of checks and balances.

The Supreme Court has previously distanced itself from the Chevron doctrine, avoiding its use in deciding cases over the past eight years. The court's conservative majority has moved towards more aggressive standards, including the major questions doctrine, which mandates explicit congressional authorization for actions with significant economic or political impacts. Nevertheless, the court has thus far refrained from fully overturning Chevron, leaving it as the controlling precedent for lower courts.

Justice Gorsuch, a well-known critic of Chevron, argued that inconsistent findings of ambiguity in lower courts demonstrate the urgent need for action from the Supreme Court. Solicitor General Elizabeth Prelogar suggested that the court could reiterate the importance of thoroughly utilizing other interpretive tools before deeming a statute as ambiguous. However, Gorsuch contended that repeated attempts in recent years to address this issue have not resolved the problem.

During the arguments, Justices Sonia Sotomayor and Elena Kagan, both liberal justices, staunchly defended the Chevron doctrine, highlighting the expertise, experience, and knowledge of agencies in making policy choices. They questioned whether deference should be given to these agencies rather than courts. However, it remains uncertain whether their arguments have persuaded any members of the conservative majority.

The Supreme Court heard over two hours of arguments in the first case, Relentless v. Department of Commerce, followed by additional arguments in the second case, Loper Bright v. Raimondo, which presented similar legal concerns. Justice Ketanji Brown Jackson recused herself from the latter case, as she had participated in it while serving on the D.C. Circuit Court of Appeals, albeit without participating in the ultimate ruling.

The court's ruling on these cases will have significant implications for the balance of power between the judiciary and the executive branch, potentially altering the landscape of regulatory oversight on various policy issues administered by federal agencies.