When Peter Cunningham, a former education department employee, tweeted that it may be time for parents to pull their children out of school until gun laws are changed, Duncan, the education secretary under Obama, responded that his family “is in.”

“This is brilliant, and tragically necessary,” Duncan tweeted. “What if no children went to school until gun laws changed to keep them safe? My family is all in if we can do this at scale. Parents, will you please join us?”