Four moderate Democrats joined Republicans on Monday in rejecting a proposal by Virginia Gov. Ralph Northam that would have banned the sale of assault weapons. Senators voted to put off a bill for a year while they ask the state crime commission to study the issue—a decision that was praised by gun advocates in the committee room. The legislation would have prohibited the sale of certain semiautomatic firearms, including popular AR-15-style rifles, and would have banned possession of magazines that contain more than 12 rounds of ammunition. Northam’s spokeswoman, Alena Yarmosky, said the governor, who has spearheaded gun-control measures, will continue to push for the legislation. “We will be back next year,” she said.