Two opposing gun initiatives will face voters on the November ballot.
Initiative 594 requires background checks on all gun sales, including internet sales and gun shows.
Initiative 591 has no background check standards that are stricter than federal law.
I-594 launched its campaign in Seattle on Thursday.
"I'm Mark and I'm a gun guy," said Snohomish County Prosecutor Mark Roe.
He's a gun owner who favors universal background checks.
"It's a minor inconvenience of making background checks extend to anyone who sells guns. Is that too much to ask to save a life?” Roe said.
"It might stop one gun death, but at what cost?" countered I-591 supporter Alan Gottlieb.
I-591 would prohibit the government from confiscating guns from citizens without due process.
Gottlieb fears more government oversight would come from I-594.
"I-594 would make every private sale in the state of Washington be reported to the state of Washington and put in the Department of Licensing data base," said Gottlieb.
Cheryl Stumbo, a survivor of the 2006 Jewish Federation shootings, is a sponsor of I-594 and believes the time has come for gun control in Washington state.
"We've had enough of the gun lobby telling us what we can and can't say. They are wrong. They are on the wrong side of history," said Stumbo.