I hate how we justify it by saying that they take jobs Americans won't. There is a ~5% unemployment rate. Without taking into account people who are transient or moving between jobs(don't wanna get too technical) thats around 12 million unemployed persons. Minus those twelve million "undocumented" workers there plenty of jobs. Of course there are gaps where we need more people to feed a growing economy and for seasonal jobs. We need to develop a progressive work program. But there is no way we should have an open boarder and just allow anyone who wants to to pour across it.