WASHINGTON — The U.S. response to the Covid-19 pandemic got politically messy. A Friday Supreme Court ruling could frustrate government responses to public health emergencies even further. The Supreme Court struck down a long-standing legal doctrine that directed judges to defer to reasonable federal agency interpretations of ambiguous or technically challenging aspects of the law. The loss of the so-called Chevron doctrine calls into question every federal agency’s interpretation of a statute, so the ruling affects the regulations of all federal agencies. ... There were other cases in which Chevron didn’t come up but that involved agencies making legal justification...
