A proposed ballot measure that would enact a string of regulations on guns is expected to qualify for the November ballot after advocates said they turned in more than 375,000 signatures to the state this week.
Also likely headed for the ballot is an initiative that would prevent cities and counties from imposing taxes on sodas or other sweetened beverages.
At a press event Friday, campaign workers for the gun-regulation measure, Initiative 1639, said they would easily clear the 259,622-signature bar to put the matter up for a vote.
The initiative is considered the most far-reaching of three gun-related ballot measures to reach the ballot in the last four years, and will test voters' appetites for tougher regulations in the wake of high-profile mass shootings around the country.
Among new restrictions, it would raise the minimum age to buy semi-automatic weapons to 21 from 18, and create a 10-day waiting period to buy one. Those age limitations already are in place for handguns.
Supporters made the case Friday that the measure could help prevent gun violence like the killings at a high school in Parkland, Florida, and the recent shooting at The Capital Gazette newspaper in Annapolis, Maryland.
"Initiative 1639 will save lives," said Stephen Paolini, the campaign manager for Yes on 1639. "It will build upon and strengthen our state's current gun laws."
Earlier this week, opponents filed an emergency request with the Washington State Supreme Court to invalidate the signatures based on concerns with the petitions used by the campaign.
The court quickly tossed the filing, although the Secretary of State's Office must still deem the petitions valid.
Alan Gottlieb, founder of the Bellevue-based Second Amendment Foundation, which filed the court challenge, said Friday his organization is exploring other ways to prevent the measure from reaching the ballot.
"There will be some form of legal action no doubt about it," he said.
Voters should oppose the initiative, Gottlieb said, singling out the proposed age limits for buying some semi-automatic rifles.
He said young people in the military can use even more powerful guns at that age and should be able to buy semi-automatic weapons as well.
He called I-1639 "a gun prohibitionist's wish list so to speak."
In 2016, voters approved a new type of protection order that allows courts to temporarily suspend a person's access to guns if there is evidence they're a threat to themselves or others.
In 2014, the public said "yes" on to a measure that put new background-check requirements on firearm sales and transfers.
In addition to limiting access to semi-automatic weapons, I-1639 would boost background checks on those semi-automatic firearms, require gun owners to complete safety training courses and hold gun owners legally responsible if a child uses a gun that was stored unsafely.
Supporters of anti-soda-tax measure, Initiative 1634, turned in more than 291,000 signatures Thursday and planned to turn in another 60,000 by Friday's deadline, The Spokesman-Review reported. They will need nearly 260,000 to qualify for the November ballot.
The measure does not prevent the state from imposing soda taxes and it would not affect Seattle's tax, which took effect this year.
The campaign supporting the measure has raised about $4.7 million, with The Coca-Cola Co. contributing $2.2 million and PepsiCo, Inc. giving $1.7 million.