Agencies can exercise discretion only in places of ambiguity or silence; they are unable to amend a clear statutory mandate that seems at odds with the purposes of the legislation. Agency did not err, and the rulemaking did not run afoul of the APA.
Agency's implementation according to statute did not offend Equal Protection; proof of discriminatory of intent would also be needed.
Mandate requiring extension of policy in the same manner and to the extent that it applies to existing facilities mans that the same methodology should be implemented to the same extent, not that the facilities should be funded to the same extent.
http://media.ca1.uscourts.gov/pdf.opinions/19-1475P-01A.pdf