Joe Biden on migrant kids who died in U.S. custody: "It's not who we are"

In a tweet on Thursday, Joe Biden mourned the 6th migrant child who died in September while detained in U.S. custody:

"Over the last year, six children have tragically died in US custody at the border. It’s unacceptable. It’s not who we are. And silence is complicity. It’s on all of us to stand up and speak out. America is a nation of immigrants. We must guarantee everyone's treated with dignity."

The big picture: Biden and many other 2020 Democratic candidates have condemned the Trump administration's policies and handlings of the border crisis. Biden has consistently run on attacking Trump's divisive rhetoric on immigration and white supremacy.

Details:

• On Monday, Customs and Border Protection confirmed 16-year-old Carlos Hernandez Vásquez from Guatemala died of influenza while detained by the Border Patrol in south Texas.
• On May 14, an unidentified 2-year-old Guatemalan boy died of a severe case of pneumonia after he was apprehended, per the Washington Post.
• In April, 16-year-old Juan de León Gutiérrez from Guatemala died in a Texas hospital after being apprehended crossing the border.
• In December, 8-year-old migrant Felipe Gomez Alonzo from Guatemala died after developing the flu.
• In December, 7-year-old Jakelin Amei Rosmery Caal Maquin from Guatemala died of sepsis.
• The death of a 10-year-old girl from El Salvador in September was disclosed on Wednesday for the first time. She had a history of medical problems and was hospitalized for months until her death.

Go deeper: On the scene: The Pentagon commits to the border crisis