Believe me, I'm as anti-illegal-immigrant as anyone.
In this case, these are not illegal aliens. There is a viswa class specifically for victims of domestic abuse. It's primarily for women and children who are abused by their spouses. Domestic violence is one grounds for deportation for legal immigrants and can get their green cards cancelled, too. Since the immigration status of the spouse is often attached to the immigration status of the violence purpetrator, there is relief from deportation for the victims so these people don't have to get shipped back with the abuser where it would be even worse for them. The strange loophole in the law is that illegal aliens cannot be deported on domestic violence because they have to be legally admitted into the country in order to be deported under the 1996 immigration changes. Someone goofed with the wording.