State's rights already exist in emergency response support from FEMA. The entire system is designed to be handled at the lowest level possible. If the local municipality or county is overwhelmed, they engage the State for support. If the State becomes overwhelmed by the response (or it exceeds their capability/capacity) they can either appeal to EMAC (basically asking other states for help) or seeking a Federal disaster declaration that allows FEMA to come to the table with additional resources, or both simultaneously. Even once FEMA is engaged because a declaration has occurred, they still cannot act unilaterally and must receive a request from the State to provide support for each requirement.
Now, if we want to have a conversation about a lowering of the bar or an increased willingness to issue Federal disaster declarations, that would be a interesting discussion. I've been doing this long enough to remember some requests for declaration being denied because they didn't meet the threshold....I haven't seen one denied in about ten years, though; basically since Sandy. If the goal is to actually push the States to be more self-sufficient in the wake of an event, then let's talk about the threshold for declaration....but we all know it's not actually about creating increased self-suffieciency, but rather being punitive.