On April 13th 2023, Missouri Attorney General Andrew Bailey announced an emergency regulation which in most cases would ban gender-affirming care for trans people in the state (link):
In an effort to protect children, Missouri Attorney General Andrew Bailey promulgated an emergency regulation clarifying that, because gender transition interventions are experimental and have significant side effects, state law already prohibits performing those procedures in the absence of substantial guardrails that ensure informed consent and adequate access to mental health care. ... The regulation outlines that in order for gender transition interventions to comply with state law, the following guardrails must be in place:
While the wording of the announcement suggests that this is only a "clarification" of the existing law, it is also described as an emergency regulation, suggesting it is new ─ and as far as I know the particular guardrails described in the regulation are not specified this way in prior legislation passed by Missouri's legislative chambers. Additionally, the announcement says:
Attorney General Bailey’s emergency regulation becomes effective April 27, 2023, and expires February 6, 2024.
But if the regulation's requirements already existed in the law, then they would already be effective even before the announcement, and would not have an expiration date (unless the existing law itself was already set to expire at that date).
This raises the question: what, if anything, gives these specific new guardrails the force of law? By my understanding, it is up to the legislative branch to decide the laws, and up to the judicial branch to interpret the meaning of those laws (e.g. what constitutes "substantial guardrails" or "informed consent" if these terms occur in the text of a law). But the Attorney General is an executive officer; he has the discretion to tell his prosecutors which offences to focus on, but not the power to decide what is or isn't an offence, unless the legislative branch has delegated that power to him somehow. But typically powers to regulate healthcare would be delegated to an executive body that is involved in healthcare, not law enforcement.
It's been reported on May 1st 2023 that a court has temporarily blocked this emergency regulation from taking effect (link), but for the purposes of this question this doesn't matter ─ I am only asking what gives the state Attorney General power to create such a regulation (if indeed it is a new regulation), not whether this regulation is likely to be found constitutional or not.