This is for Massachusetts-
http://www.haphousing.org/default/index.cfm/renters/rental-assistance-programs/section-8-faqs/
Section 8 housing vouchers do not give them based on 'preference' or who gets them 'first'. They base it on the waiting list that they maintain (which in many states are years long and in some states they may not give out ANY vouchers some years because they've hit their limit), your name comes to the top you're next in line to get a voucher. As I understand it that's true in Texas. I have a deaf-blind friend who has had section 8 housing in both Oklahoma and Texas (some good some bad) but I don't think they give the housing to Domestic violence survivors or to single mothers first over disabled... that's poppycock.