The 2020 Democratic presidential candidates are far more forceful and united on gun control than their predecessors, endorsing a wide range of policies that past nominees sidestepped or rejected , according to a New York Times survey of the 19 campaigns .

The political terrain on guns has been shifting for several years in response to a seemingly unending series of mass shootings and a newly emboldened network of advocacy groups. Policies that were dividing lines among Democrats have become baselines, and proposals that were politically untouchable are now firmly on the table.

All 19 candidates support an assault weapons ban. The biggest disagreement: whether people who already own those weapons should be required to sell them to the government, or simply given the option to do so. There is also some support for a federal gun registry, an idea that many Democrats used to dismiss exasperatedly as gun-lobby scaremongering.

Former Vice President Joseph R. Biden Jr. is calling for a ban on all online sales of guns and gun parts , an unusually aggressive proposal . Senator Elizabeth Warren wants a 30 percent excise tax on guns and a 50 percent excise tax on ammunition. Thirteen candidates want to require a license to own a gun.