Julián Castro is ostensibly still the Secretary of Housing and Urban Development, a post he’s held since 2014 after he resigned as mayor of San Antonio. But according to Politico, the Texas Democrat seems to have spent a lot of his 18 months in Washington getting ready for the next job: vice-presidential nominee.

“At home, Julián Castro’s been spending more time reading and watching television in Spanish, trying to get his speaking skills up to speed,” writes Edward-Isaac Dovere. “On the job as Housing and Urban Development secretary, he’s been carefully working the levers in Washington, with coaching from Bill Clinton and a twin brother who’s a popular and up-and-coming congressman himself.”