Castro's announcement was first published by 'The New York Times' via a campaign video. He also took to Twitter to share the news. . As former San Antonio mayor and Obama administration HUD Secretary, Castro had a progressive campaign. He supported "Medicare for all," immigration and criminal justice reform, and climate change initiatives such as the Paris Accord and Green New Deal. According to CNBC, Castro was only able to raise $3.5 million in the third quarter of 2019, . which was significantly behind funds raised by leading Democrats Bernie Sanders and Elizabeth Warren.