3 things we're watching in Washington's presidential primary on Tuesday

Voting ends Tuesday in Washington state's presidential primary , as President Biden and former President Trump appear headed toward a rematch in November.

Why it matters: Washington's primary may give Trump the final delegates he needs to clinch the Republican nomination, AP reports .

• Biden could also lock down the Democratic nomination on Tuesday. He needs only about 40% of the delegates that are at stake in Tuesday's elections, which include primaries in Georgia and Mississippi, per AP.

Context: In Washington's vote-by-mail elections, it's typical for only about half of ballots to be counted on election night.

• That means it might take days before it's clear exactly how many delegates each candidate has won.

Here are a few things we'll be watching as early results roll in around 8pm Tuesday.

The "uncommitted" vote

Democrats who want Biden to call for a permanent ceasefire in the Israel-Hamas war have been urging other Democratic voters to pick the " uncommitted delegates " option on the ballot as a form of protest .

How it works: If at least 15% of Democrats statewide or in any of Washington's 10 congressional districts choose "uncommitted," Washington will send a pool of delegates to the Democratic National Convention who aren't bound to vote for Biden or any specific candidate when the party chooses its presidential nominee.

How low turnout goes

Turnout in the 2020 presidential primary was 49.55% statewide , and the Washington's secretary of state's office told Axios it is expecting similar participation in 2024.

Yes, but: It's possible fewer voters will return their ballots this year, since both parties' presidential nominees are a near certainty .

State of play: Of the candidates who appear on Washington's Democratic primary ballot, only Biden and self-help author Marianne Williamson are still in the race.

• On the Republican side, all the 2024 candidates besides Trump have already ended their presidential campaigns.
• By contrast, in early March 2020, Bernie Sanders was still campaigning hard for the Democratic nomination.

If there's an anti-Trump vote

The former president only garnered about 38% of the statewide vote in November 2016 and just under 39% in 2020.

Flashback: In 2016, about 25% of Washington's Republican primary voters cast ballots for other candidates, even though by then Trump was already the presumptive GOP nominee.

A similar situation could play out this year, even though Trump is once again the last Republican candidate standing.

• Because Washington finalized the names on the primary ballot in January, Republicans will be able to cast ballots for former contenders Ron DeSantis , Nikki Haley , Vivek Ramaswamy or Chris Christie .

Reality check: None of those ex-candidates are likely to win Washington delegates, as Republican party rules say all a state's delegates will go to the candidate who wins more than 50% of the primary vote.

What's next: Ballots must be returned to an official drop box by 8pm Tuesday or postmarked by Tuesday to be counted.

Go deeper: What to know about voting in Washington's presidential primary

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