Think about this: why do people work in sweatshops, or at less than minimum wage at all? It's because, if you're a poor Mexican, it's the only job you can get, and
it's better than any alternative. If you weren't working in the sweatshop, you wouldn't have a job at all. You can't force companies to pay them more, because you cannot legislate basic economics. If a worker's labor is worth $2 an hour, it is worth $2 an hour, and as long as someone is unemployed and willing to do the job, $2 an hour is a lot better than $0 an hour. Companies are not "oppressing" the illegal immigrant (borders should be completely open, in my opinion) working in the kitchen by paying him less than minimum wage. That is the wage he has agreed to, and the wage which market forces dictate. By making it illegal to do so, you just make the owner take it off the books. That's why I believe the minimum wage should be abolished. It serves no purpose: if a job is worth more than the minimum wage, it is irrelevant, and if it is worth less, then it is either given out illegally, anyway, or, ironically, not at all, if the government inspectors have their way. In no case can companies realistically actually pay any more.
A lot of this comes from lawmakers' unrealistic views of how the world is: if I legislate that a job, or an apartment, or whatever is worth a certain amount, guess what, it's really still worth as much as it was before.
Economics in One Lesson: The Shortest and Surest Way to Understand Basic Economics is a book everyone should read: it explains just why all these attempts by the government, like rent controls, union regulations, tariffs, and minimum wages, can never work and are, in fact, counter-productive. It was written in 1946 (and benefits from not having to treat FDR like the Great American Saint), but it's still just as relevant.