First of all, courts aren’t ruling on the merits of regulations, only on whether they were enacted with valid authority and following the correct procedure (inc

First of all, courts aren’t ruling on the merits of regulations, only on whether they were enacted with valid authority and following the correct procedure (including not being arbitrary and capricious). And the overturning of Chevron has nothing to do with how courts handle technical expertise behind statutes - it’s only about adjudicating the validity of regulations, not of statutes. So the rest of my comment discusses the case when opinions from a regulatory agency’s technical experts are somehow relevant to whether a regulation is valid and not just to the regulation’s merits or lack thereof. Judges are still either encouraged or expected (I forget which) to give due respect to the agency’s technical experts, based on pre-Chevron precedents. They’re definitely not forbidden from doing so. But for example, what if the challenger also presents technical expert opinions which run counter to the argument of the agency’s expert? Under Chevron, the court had no authority to conclude that the challenger’s expert-informed argument was more likely to be right than the agency’s expert-informed argument when both arguments are reasonable. Now that Chevron is overturned, the court does have that authority. Just like in every other case outside the former scope of Chevron where one or both of the parties presents expert opinions to the court. That’s it. Honestly, overturning Chevron is mainly as impactful as it is because Congress isn’t sufficiently active at legislatively clarifying its vague statutory grants of regulatory authority or removing some of the more important substantive decisions from the whims of frequently changing executive branch administrations. In a parliamentary system where the government is supported by a legislative majority, both the laws and the regulations can be adjusted as needed, not just the regulations.