A bungled message from a South Texas housing authority prompted mass flight. The situation in Port Isabel offers a glimpse of what could happen nationwide if a Trump administration proposal takes effect to end housing assistance to families in which at least one member is in the country illegally. The U.S. Department of Housing and Urban Development wants to reverse a policy in effect for decades that allows families with at least one person with legal status to occupy a home as long as those here illegally pay a full, unsubsidized share of rent. Advocates estimate up to 80,000 people may lose their homes.