Democratic lawmakers are pushing stricter gun laws in statehouses across the country, emboldened by sweeping electoral victories in 2018 and confident that public opinion is on their side a year after the school shooting in Parkland, Florida.

Last year's wins handed Democrats control of the governorship and legislature in several more states, including New Mexico, New York, Colorado, Maine and Nevada, and lawmakers are using their new power to draft or pass gun laws.

In Colorado, Tom Sullivan spent years urging lawmakers to tackle gun violence after his 27-year-old son, Alex, was killed in the 2012 movie theater shooting there.