I think illegal immigrants should be given a path to citizenship. They're here and if they aren't committing crimes they should be given the opportunity to be as free and productive as everyone else. As citizens they would all have to pay taxes and employers could not pay them so little. Paying illegal immigrants such low wages hurts both the workers and other citizens who are pushed out because they have to be paid more. You guys should also note that many illegal immigrants do pay taxes.
That said, I don't think there should be totally free immigration. That would be a security risk. I do think it should be made easier so that good people who just want more economic opportunity can come here and thrive.
America has a long history of shitting on its immigrants until there are so many that they can't do it anymore (see Italians, Irish etc.) I think we should take a more enlightened view now. How many of your relatives came from Europe? Why is Mexico any different?