After a marathon committee hearing, Colorado Democrats’ bill to ban the sale of semi-automatic rifles and other so-called assault weapons cleared its first hurdle early Wednesday morning and now is poised to pass the full House.

The measure, House Bill 1292, passed the House Judiciary Committee on a 7-3 party-line vote. The wide margin came 11 months after the same Democratic-majority committee narrowly voted to kill a similar bill.

This year’s proposal would ban the sale, purchase, transfer or manufacture of “assault weapons.” The bill’s definition of those firearms includes semi-automatic rifles and pistols that have fixed, large-capacity magazines or have the ability to accept detachable magazines, along with various other characteristics and other types of high-powered firearms. The bill does not ban the possession of the weapons.

More than 550 people signed up to testify for and against the bill during the House Judiciary Committee’s hearing. It began Tuesday morning and ended just after midnight Wednesday with the vote.

Supporters cast the bill not as a silver bullet solution to gun violence but as a response to the mass shootings that have plagued Colorado and the rest of the country for decades.

The steady drumbeat of those horrors in Colorado were inextricably wound into the bill and into the hearing: The panel’s vote came two days before the three-year anniversary of the Boulder King Soopers shooting that killed 10 people, and half of the Judiciary Committee’s members represent cities that have had mass shootings in recent memory.

“We know about the ever-present threat of mass shootings, public shootings, with few to zero injured survivors but fatalities in the double digits. … We know that those continue unchecked but for courageous, data-driven policy change,” said Rep. Elisabeth Epps, who’s sponsoring the bill with Rep. Tim Hernández. Both are Denver Democrats.

The measure now heads to the full House, where it has a strong chance of passing a chamber dominated by a Democratic supermajority.

If the bill does pass the House, that would put it on something of a collision course with the state Senate: The lawmaker who’s led the charge on gun reform there — Sen. Tom Sullivan, whose son Alex was among the victims of the 2012 Aurora movie theater shooting — has expressed concerns about the efficacy of pursuing a ban targeting high-powered firearms. He has said the bill would not save as many lives as other gun legislation under consideration.

The measure doesn’t yet have a Senate sponsor, though Hernández said Wednesday morning that a handful of senators are interested.

A precursor to the bill died in House Judiciary last April, also on the anniversary of another Colorado shooting: the 1999 Columbine High School massacre.

This year’s bill was amended following the end of testimony to allow for weapons to be passed down to designated heirs after their owner’s death. Epps and Hernández also changed the penalties for violating the bill. Initially, the measure would’ve levied $250,000 and $500,000 fines. Now, the bill makes it a petty offense to sell or purchase the firearms.

Supporters said that change was in response to concerns from the public about the scale of the fines. The change also means the bill goes directly to the House floor, bypassing the House Finance Committee. That committee is still Democrat-controlled, but it has a tighter majority — and two of its Democratic members helped kill the bill in the Judiciary Committee last year.

Despite the bill winning initial approval, some committee Democrats expressed concern about specific provisions. Opponents had said the bill was so sweeping that it would cover more firearms than those that are generally considered to be “assault weapons,” and Rep. Leslie Herod — who voted for the bill — said she thought some aspects of the measure may be overbroad.

Critics, including Republican lawmakers, gun shop owners and firearms instructors, blasted the bill throughout Tuesday’s hearing. It amounts to government overreach that will decimate the firearms industry here, they said, while not doing enough to stem the tide of gun deaths.

“I like things that work. And unfortunately from the perspective of public safety, I don’t think that this is going to work,” said Rep. Gabe Evans. The Fort Lupton Republican argued that recent gun-reform bills passed in Colorado haven’t borne fruit.

Opponents frequently criticized Democrats for not increasing security in schools and other public spaces that have been the sites of mass shootings. Rep. Jennifer Bacon, a Denver Democrat, countered that lawmakers have spent millions to better protect schools and bolster police forces.

That hasn’t worked, she said.

“What this bill does is it signals change,” Bacon said. “It is a different thing, expecting a different outcome. We are the state of Columbine, of Aurora, of Littleton and King Soopers. We have been put on the map for those things. So I would like to put us on the map for signaling change — that we expect to have a sane approach to try to solve for this.”

Stay up-to-date with Colorado Politics by signing up for our weekly newsletter, The Spot.