You're conflating two groups. There are legal immigrants who stay, generally under the sponsorship of a company, and there are illegal immigrants who either come by illegally crossing the border, or by overstaying a legally obtained visa. Legal immigrants do tend to be highly skilled and relatively highly paid, though their wages are often lower than citizen workers in the same field - which can depress wages overall. Illegal immigrants by contrast tend to be involved in low skill and low pay labor, often done under the table.

Personally, I have nothing at all against the illegal sort. Day laborers, for instance, tend to be great workers and good people, happy to put in a hard day's work for a $50 and some good meals. At the same time though, I have to consider that this is really distorting the economy since it drags down wages for all people willing to do this work to that level, which is not really fair to people that want to make a living doing this work but want a higher standard of living, to raise a family, etc.

Not illegals. You realize that as an illegal you cannot legally work in the states right? You have no documentation, so anywhere paying decent wages would never hire you, because it's illegal and would open them up to fines and other legal issues. The only places that are going to hire you are going to do it under the table, pay you extremely low wages, and basically take advantage of you because you have no power.