Actually a majority of the homeless are mentally ill, so thats out.
Existing immigration laws would do much, but really I think you make it a felony for any business to hire someone that is not a legal immigrant. Then anyone renting to an illegal immigrant, and so on. When they can't find work, a place to live, etc they will go home. Oh and let's make it a felony for anyone in the government granting them social security cards, welfare, drivers licenses, or any services! Hell that would probably help us with the deficit too.

Also for all those seeking immigration reform and basically want us to open the boarders and give the over 11 million illegals that are here amnesty, I say I have NO PROBLEM with anyone that has come here LEGALLY. Illegals are criminals, and need to be treated as such.