Updated at 10:30 a.m. ET
Julián Castro, the only Latino candidate in the Democratic field, has ended his presidential campaign.
Castro released a video on Twitter on Thursday, saying that his campaign had "stood up for the most vulnerable people" and had "given a voice to those who are often forgotten."
He adds in the video: "I'm not done fighting. I'll keep working toward a nation where everyone counts."
Castro served as secretary of housing and urban development in the Obama administration and, before that, was mayor of San Antonio, Texas.