WASHINGTON (TNS) — Democrats have a familiar response after every mass shooting: Expand background checks.

Some liberals say that's not good enough anymore.

In the aftermath of the Las Vegas shooting that left 58 dead and more than 500 wounded, a collection of operatives and longtime gun control advocates are trying to persuade Democrats to think bigger. Rather than focus on expanding background checks, they argue the party should be talking about banning some types of guns outright, restricting open carry, and even creating a national licensing system.

It's a step many of them think is not only good policy but good politics, convinced that aggressive measures are both supported by most voters and will energize progressives.

"The Democrats' problem on guns is in parallel to a larger party problem, which is a tendency to mumble about something we think we might get, rather than saying what we actually want," said Mark Glaze, former executive director for Everytown for Gun Safety.

The push for a more aggressive posture is rejected by many Democrats and gun control advocates, who say more discreet policy proposals, such as expanding background checks, will both reduce gun deaths and play well with more voters. Many of them say the fact Democrats are united behind those measures is a remarkable achievement on its own, especially given the party's traditional reluctance to support gun control in any way for fear of alienating culturally conservative voters.

Indeed, this week congressional Democrats have by and large stuck to calling for expanded background checks and banning "bump stocks," which authorities believe Stephen Paddock used to increase his rate of fire during the deadly shooting in Las Vegas.

Yet, even as Republicans appear to be ready, with the NRA's blessing, to consider restricting bump stocks, liberals want Democrats to demand more. To Glaze and his allies, focusing on narrow fixes misses a larger shift within politics and the Democratic Party, which has been buttressed by an influx of energy from progressive activists since the election of President Donald Trump. They think the party would benefit from moving to the left on the issue to stoke its base, similar to arguments many other liberals have made on issues like single-payer health care or tuition-free college.

"When we keep mumbling about background checks, it kills base enthusiasm," Glaze said. "And that's not a recipe for winning."

Glaze is now a senior adviser to Guns Down, a group that advocates for what officials there see a bolder approach to gun control legislation. Officials there argue that in addition to rallying progressives, their proposals are broadly popular with the public.

The group released a poll in June that found broad majority support for a handful of proposals not normally discussed by Democratic leaders, such as banning the open carry of loaded weapons and creating a national gun registry.

"The public is with us on this if there were strong elected leaders who advanced these kinds of bold solutions, instead of baked-in compromises, like closing the terror loophole," said Igor Volsky, director of Guns Down.

In its survey, the only item that didn't receive majority of support was banning private ownership of handguns, which just 33 percent of the public backed.

The politics of gun control, of course, are not so easily boiled down in one poll. A Gallup poll released late last year found that support for a ban on semi-automatic assault rifles was at an all-time low, with just 36 percent of Americans in support of it.

The party also faces an extra complication because many of its incumbent senators, including a handful of them up for re-election this year, hail from red states where any form of gun control legislation will be less popular.

Many leaders in the gun control community bristle at the suggestion that their strategy is at fault. To them, on both the substance and the politics, expanding background checks is the best approach.

"We do see that universal background checks work, they save lives," said Peter Ambler, executive director for American for Responsible Solutions, a gun control group co-founded with former Democratic Rep. Gabby Giffords. "That can be our North Star. We're going to do what works but not necessarily what feels good for ideologues on one side or the other."

Ambler's group is not liberal or Democratic, but its approach to legislation carries enormous weight in the party. And its opinion on background checks is shared by other Democrats.

"I'm not suggesting there are no other policy suggestions worth pushing, but candidly, I think notion that you're suggesting here that a registry of assault weapons would be a more radical or effective solution than universal background checks is a wrong or false premise," said Brian Kavanagh, a Democratic New York assemblyman and founder of the American State Legislators for Gun Violence Prevention.