President Biden formally clinched the Democratic nomination on Tuesday, AP projects, setting up what is expected to be a tense rematch with Republican Donald Trump of the 2020 presidential election.

Why it matters: The Biden campaign has already pivoted to the general election, as the president's team seeks to present Trump as an existential threat to the nation.

• Biden's victory comes after he delivered a fiery State of the Union address last week, when he baited Republican skeptics and tried to quell voter concerns about his age.

Driving the news: Biden in a statement after his projected nomination said he was "honored that the broad coalition of voters representing the rich diversity of the Democratic Party across the country have put their faith in me once again to lead our party … in a moment when the threat Trump poses is greater than ever."

• Biden was projected to win primaries in Mississippi and Georgia shortly after polls closed. Votes were still being counted in Washington and the Northern Mariana Islands. Democrats living abroad also voted on Tuesday.
• The president was closing in on the 1,968 delegates needed to clinch the party nomination heading into Tuesday's contest after he dominated Super Tuesday and every prior Democratic primary.
• Biden, who did not face any real challenge from his long-shot opponents, has faced some opposition from Democrats seeking to protest his support for Israel's government in its war with Hamas by voting "uncommitted."

Zoom in: Earlier this week, Biden leaned into voter concerns about his age head-on, saying in a recent TV ad: "Look, I'm not a young guy."

• "That's no secret, but here's the deal: I understand how to get things done for the American people."

What he's saying: "I believe that the American people will choose to keep us moving into the future," Biden said in a statement before AP projected Trump had won enough delegates to clinch the Republican presidential nomination.

• "With every crisis, America has always emerged stronger and more united on the other side. This November will be no different — and I believe we will do it together."

What to watch: Biden already has a huge cash advantage over Trump, who is also expected to formally clinch his party's nomination soon.

• The Biden-Trump rematch is expected to be one of the longest presidential campaigns in recent history.

Go deeper: State of the Union fuels Biden's biggest fundraising day of campaign

Editor's note: This article has been updated with comment from President Biden and with more details from the primaries.