Only one-third of illegal immigrants are from Mexico; the majority are from Europe or Asia. Most did not enter the United States illegally; they are employees or students who overstayed their visas. They have the same income profile as the general population. They have better health and lower incarceration rates. They pay the same taxes you do and more. They do not receive "free" public education or any form of welfare. Overall, annual taxes paid by workers without documentation to all levels of government more than offset the cost of services received, generating a net annual surplus of $25 to $30 billion. Oh yes, one more thing: the Robert Rector/Heritage Foundation "study" is nearly thoroughly bogus.
Almost nothing you have read, heard, or been told by frothing conservatives about illegal immigration is accurate.
It's a large document and requires some reading and thoughtful understanding, something conservatives are mostly incapable of or naturally loathe to do. That's the only "Immigration Problem" we have in this country: ignorance, xenophobia, and bigotry.
Update (12/2): Welcome Topix forum readers! Yes, you are conservative idiots. Yes, you.