“Until I do not have a breath left in my lungs, I’ll stand up for the safety and security of all Virginians,” Northam said in a statement.

Though Republicans and gun-rights groups have resisted calls to ban assault weapons, calling the term ill-defined and overreaching, proposals to ban bump stocks appear to be building broad support. The Vegas shooter used the devices, which convert semi-automatic rifles to function as if they were fully automatic, to rapidly spray bullets into a crowd at a country music concert, killing 58 people and wounding more than 500.

Ed Gillespie, the Republican candidate for governor, said Friday that he also would support banning or regulating bump stocks.

“It seems pretty evident to me that we rightly outlaw automatic weapons in this country and that bump stocks effectively serve to get around that law,” Gillespie said.

Gillespie said he understands the “emotional response to do something” after a mass shooting, but data show that violent crime has gone down as gun ownership has risen.

The head of the Virginia Citizens Defense League, a gun-rights group that lobbies at the General Assembly every year, sent an email to his members Tuesday night urging them to “stay in the fight” after Las Vegas.