Beto O'Rourke joins Klobuchar and Buttigieg in endorsing Biden

We need someone who can bring us together and heal us. We need Joe Biden."

• The endorsements come just hours before polls open on Super Tuesday. Sen. Bernie Sanders holds a narrow lead in delegates over Biden, but moderates coalescing around Biden could give him a vital boost.

What he's saying: At the rally, Biden praised the gun control advocacy of O'Rourke — who campaigned for buybacks of assault weapons and who declared last year, "Hell, yes, we're going to take your AR-15, your AK-47.

• "You're gonna take care of the gun problem with me, you're gonna be the one who leads this effort," Biden told O'Rourke. "I'm counting on you, we need you badly."

The big picture: O'Rourke dropped out of the 2020 race in November after multiple attempts to rebrand himself in the Democratic field. He'd once been the buzz of the Democratic Party after making a splash in the 2018 midterms while running against incumbent GOP Sen. Ted Cruz.

Go deeper: Joe Biden's sudden, shocking surge

Editor's note: This article has been updated with new details from the rally.