2016 Postmortem

supports affirmative action. Also:

In April 2016 Castro was criticized by various community, Democratic, and progressive political groups for facilitating the sale of thousands of foreclosed houses to Wall Street firms at steep discounts through HUD's Distressed Assets Stabilization Program (DASP).[39] More than 98% of the recently-sold homes were sold to Wall Street firms. [40] Advocates sought a reduction of principal for troubled homeowners and a sale of mortgages to nonprofits instead of private equity firms.[41]

The mortgage sale criticism has led to sparring between Democratic political figures. Forty-five members of Congress wrote a letter to Castro demanding reform of DASP.[42] The criticism of Castro led to counter-criticism from some quarters, and a member of the board of American Family Voices, one of the groups critical of the HUD policies, resigned in protest.[43]
Political positions

Castro has been an advocate for LGBT rights and as mayor opposed the law in Texas (later overturned by the US Supreme Court) that denied legal recognition to same-sex marriages.[44]

https://en.wikipedia.org/wiki/Julian_Castro

DUers have long cited him as a potential running mate for Hillary. Obama nominated Castro as Secretary of HUD, though I don't know what credentialed him for that nom; and Castro resigned as Mayor to take a position as HUD Secretary. I don't think anything in these two lines is unrelated to the others.