You should probably start by reading SCOTUSblog's Supreme Court strikes down Chevron, curtailing power of federal agencies for a largely neutral view. In brief, By a vote of 6-3, the justices overruled their landmark 1984 decision in Chevron v. Natural Resources Defense Council, which gave rise to the doctrine known as the Chevron doctrine. Under that doctrine, if Congress has not directly addressed the question at the center of a dispute, a court was required to uphold the agency’s interpretation of the statute as long as it was reasonable.I discussed Chevron briefly in Kavanaugh’s views on EPA’s climate authority, without really focussing on the principle.
If you want to read someone wringing their hands about how terrible the decision is, you can try UnSciAm's A Supreme Court Ruling May Make It Harder for Government Agencies to Use Good Science. You should be cautious about believing the article though; for example "it was an unremarkable reminder of judicial restraint that had been the norm for a century" is doubtful; an attempt to prevent you thinking "but hold on this is just restoring things to how they were before". But inadvertently their A particularly important feature of Chevron deference, he says, is its nonpartisan nature. “It is a neutral principle,” Doniger says. “It lets conservative administrations cut back on the scope of these laws, and it lets liberal administrations do more with them” is quite telling: pretending that this is entirely or primarily a matter of scientific expertise is bollox: raw politics comes into it. And having the law change under your feet when the administration changes is not good. Another blow against the "scientific expertise" idea is the case actually under discussion, which amounted to who should pay for agency monitors on fishing boats. Oddly, the agency wanted the fishermen to pay.
To return to the basics: law (cough legislation cough) requires making, and that is down to the legislature; execution, and that is the job of the executive; and interpretation, which is what judges are for. Having the executive get to both execute and decide the law is dubious, and an obvious violation of separation-of-powers. Few people will object to the agencies resolving minor ambiguities; but major questions are a different matter. Speaking of which, the judgement helpfully points out that the Supremes haven't actually upheld Chevron for years. But as quite a few have pointed out, it will remain common for courts to actually defer, particularly in technical instances1.
There's a fairly strong theme of people making up their minds pro and con on this matter based on the results they want, not the principles; vide UnSciAm, who correctly judge that the bulk of their subscribing readership come from amongst those likely to be in favour of regulators having more power. Another issue I've seen is defenders admitting that Congress routinely writes poor quality legislation that begs for interpretation. That shouldn't be a defence; if (but its unlikely) this acted to wake up Congress and get them to write better quality legislation, that would be nice.
Wiki quotes the NYT (arch) that this was the "cumulation of the current Supreme Court's efforts to weaken the adminstrative state as part of a conservative agenda against big government"; that seems to me to be typically poor thinking, since I see no reason why it should be the culmination (ah: I should have actually read the article: their point is that Chevron was the point, not Row vs Wade; this is more plausible; it also rather nicely suggests that the left is easily fooled since it concentrates so hard on stuff like RvW and none of its people really care about stuff like C; vide the relative lack of coverage and the total lack of popular interest).
Refs
* Not to be mistaken for City of New York v Chevron Corp, again,
* WV v EPA.
Notes
1. The judgement prefers "respect" to "defer", and perhaps that's right: The Court recognized from the outset, though, that exercising independent judgment often included according due respect to Executive Branch interpretations of federal statutes. Such respect was thought especially warranted when an Executive Branch interpretation was issued roughly contemporaneously with enactment of the statute and remained consistent over time. The Court also gave “the most respectful consideration” to Executive Branch interpretations simply because “[t]he officers concerned [were] usually able men, and masters of the subject,” who may well have drafted the laws at issue. United States v. Moore, 95 U. S. 760, 763. “Respect,” though, was just that. The views of the Executive Branch could inform the judgment of the Judiciary, but did not supersede it. “[I]n cases where [a court’s] own judgment . . . differ[ed] from that of other high functionaries,” the court was “not at liberty to surrender, or to waive it.” United States v. Dickson, 15 Pet. 141, 162.
