The former San Antonio mayor and secretary of housing and urban development (Hud) under Barack Obama has already held events with prospective donors for a 2020 campaign. He told Rolling Stone in October that he is “likely” to run. Among all of the speculated contenders in the 2020 presidential race, Castro will probably be the only prominent Latino Democrat. The 44-year-old has been a rising star in the Democratic party since he became mayor of one of the country’s largest cities in 2009. Three years later, he was the first Latino to give a keynote speech at the Democratic national...