Castro gained national attention in 2012 when he was the first Hispanic to deliver the keynote address at a Democratic National Convention in Charlotte, North Carolina. Following the 2012 elections, Castro declined the position of United States Secretary of Transportation, partly with an eye on running for governor of Texas after 2017. However, in 2014, Castro accepted President Barack Obama's offer of the position of United States Secretary of Housing and Urban Development. Castro resigned as mayor effective July 22, 2014, so that he could take up his duties in Washington. The San Antonio City Council elected councilmember Ivy Taylor to replace him.