Rep. Pramila Jayapal, the co-chair of the Congressional Progressive Caucus, endorsed Sen. Bernie Sanders for president on Sunday.

Why it matters: With Jayapal's endorsement, Sanders has the backing of both CPC co-chairs, after Rep. Mark Pocan endorsed him last week. He also has the support of influential progressive Reps. Alexandria Ocasio-Cortez, Ilhan Omar and Rashida Tlaib.

Ocasio-Cortez called Jayapal's endorsement of Sanders a "[r]eally big deal." "Pramila is a major leader in the House, carries the Medicare for All bill & co-chairs the Congressional Progressive Caucus," she tweeted.

The big picture: The endorsement was seen as a blow for his fellow progressive 2020 rival Sen. Elizabeth Warren.

Sanders lost out to Warren and Sen. Amy Klobuchar later Sunday for the New York Times editorial board's endorsement for president.

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