The national organization of middle and high school leaders is urging the Biden administration to do more to protect its members from “threats and violence” by parents who disagree with COVID-19 restrictions they put in place. In a call for support, the National Association of Secondary School Principals (NASSP) on Thursday said its members have been faced with “hostile community members” because of their policies on “highly charged issues” involving masks, quarantines, and vaccines. The organization cited the confrontation between Teresa M. Hill, the principal of Walden Grove High School in Arizona, and a group of people who wanted to discuss with her a student who was prohibited from returning to class after possibly being exposed to someone who tested positive for COVID-19. “One month ago, seven people refused to leave our campus demanding a quarantined student attend class. After a lockdown of the front office for three hours, we …