President Obama mixed a powerful appeal for curbing gun violence with visible executive action to convey his determination to honor the memory of the victims of the Sandy Hook school massacre. In the month since 20 first-graders were gunned down, shocking the nation’s conscience, 900 more Americans have reportedly died at the end of a gun, Obama said. With four children on stage with him at the White House who had written letters urging he take action, Obama unveiled a specific set of proposals and vowed that “in the days ahead I intend to use whatever weight this office holds to make them a reality.”