The Illinois capitol was a site of celebration on Tuesday, as state legislators passed a ban on military-style firearms. The legislation made Illinois the ninth US state to enact a ban on such weapons, which have been used in many of the country’s most devastating mass shootings. “Illinois now officially prohibits the sale and distribution of these mass killing machines and rapid-fire devices,” the Democratic governor JB Pritzker said as he signed the bill. He added: “We must keep fighting, voting and protesting to ensure that future generations will only have to read about massacres.” In recent years, the US...