What's wrong with Immigration?

Is immigration really that bad? Why? I'd rather give immigrants here a job if they will then spend the money here... it would help the economy more than companies sending the factory down to mexico.  At least if they live here, and buy things here, it will help the economy here, rather than the alternate... as I said.. our companies go searching elsewhere for cheaper labor.  What do you all think?

The problem with immigration is that immigrants usually provide cheap labour. Cheap labour reduces the wages of citizens who had been working that job and some of them lose their job or resign because they can't afford to work for so little. I guess this is the same problem as outsourcing.