Those with FAMILIES here will do that. They will buy a home here. They will pay taxes. etc.
BUT, THE MAJORITY of the illegals that are here, are here to work and then send their money BACK HOME. Heck the Mexicans will drive to Mexico and buy a trailer of goods that they then bring back without buying local. 

I know a number of illegals, and I can say that those that have kids here SHOULD be allowed to stay. Those without should be send home.  And as to the kids that stay, if they were brought here illegally, and have at least 3-4 years in our schools and is either still in school OR has GED/better, should be allowed to stay. Those that did not attend our schools, or has dropped out, should NOT be allowed to stay. SImple as that.