EVERETT — Washington is opening the election process to thousands of new voters in the upcoming primary, none of whom will be 18 when they cast their ballots.

In a close contest, they could influence the outcome.

Until now, a person could only vote in an election as long as they turn 18 on or before the day of the election. They also must be United States citizens that have lived in the state, county and precinct for at least 30 days preceding an election.

A provision in a 2020 state law kicked in this year. It allows any 17-year-old to vote in the August primary, as long as they will be 18 by the general election.

This gives hundreds of teens in Snohomish County a chance to help winnow the field — maybe decide the outcome — in contests with three or more candidates, say for a legislative seat or congressional office.

“Every vote counts — including in our primaries,” Snohomish County Auditor Garth Fell said. “Seventeen-year-old, primary-only voters will have an opportunity to decide which candidates move forward to the general. And in close races, their votes may be enough to make the difference.”

Democratic lawmakers pushed for the change in 2020. It’s been a priority of their party.

“By allowing 17-year-olds to vote in the primary, they are given a voice in our electoral process and actually help determine who will be on the general election ballot — something they’d previously been excluded from. This leads to increased political engagement among this demographic and better representation on the ballot,” Olivia Heersink, communications director for the state Democratic Party, in an email.

Eligible teens don’t get to weigh in on every issue. Measures that will be decided in the primary such as a school district or fire district levy won’t appear on their ballots. They will only get ballots with contests that will also be on the November ballot.

“This is exciting for our young voters to have more of an opportunity to help decide who gets through the primary and have an impact on who gets to represent them,” said Caleb Heimlich, chair of the state Republican Party.

In Snohomish County, there were 945 17-year-olds eligible to participate in August as of Thursday. Island County had 51, as of June 15.

Because it is a new thing, each 17-year-old can expect to receive a letter from county election officials explaining why they get to vote and why their ballot might look different than others in their family in the primary.

“For this election, it’s not a big impact,” said Michele Reagan, the county’s elections supervisor.

That 2020 law, authored by Sen. Marko Liias, D-Everett, laid out a process for pre-registering 16- and 17-year-olds and adding them to the statewide database when they are eligible to vote. That bill had critics. Some expressed concerns about inadequate protections of the identity of the minors. Others worried about the cost of carrying out the new mandates. In the end, the bill passed without Republican votes.

As of early June, there were 42,500 participants in what’s known as the Future Voter program, including 17-year-olds who will be getting primary ballots.

Allowing them to take part in August “is a great way to demonstrate to them their voice matters,” Secretary of State Steve Hobbs said. “The act of voting instills confidence and reassurance in our democracy.”

Jerry Cornfield: 360-352-8623; jcornfield@heraldnet.com; Twitter: @dospueblos.