- Congress is allowed to delegate to the executive (agencies)

- but if an agency goes so far in beyond the original understanding of its delegation as to cause a major political controversy, then it has overstepped its mandate

For example, if Congress were to delegate to the EPA the power to ban internal combustion engines at the EPA's choice, then the EPA could absolutely do that. (Perhaps Congress couldn't if the court revisits Wickard, who knows, but if Congress could, then so could EPA). But if Congress were to pass a bill regarding clean air and decades later the EPA decides that a clean air mandate means the EPA can ban ICEs, then that would clearly be a major question (well, today it would be; maybe in another two decades it wouldn't be), the courts would not (today) allow such a regulation, and EPA would have to go ask Congress to ban ICEs or to delegate that authority to the EPA.

> This feels like a recipe for the unelected branch (the courts) to run everything.

If the courts were to decide that EPA can't ban ICEs under the Clean Air Act but that the courts can, that would be pretty insane. Perhaps before Chevron the courts sometimes did that sort of thing, but they wouldn't now if Chevron is reversed because this SCOTUS absolutely does not want that and will write an opinion that reflects that -- that much is clear. So I think this is hyperbole. Instead if Chevron is reversed, and together with W. Virginia vs. EPA, "major questions" will not be decided by the courts -- major questions would go undecided as long as Congress leaves them undecided, with the status quo preserved. That would not be a bad outcome!