We have plenty of evidence of what happens to wages when the Feds haven't spoken, and when the labor pool isn't allowed to unionize. It isn't good for the middle class. Setting a minimum wage establishes a base level of pay that even the most powerless (economically) can earn. It also provides a base from which more skilled workers can bargain. Will it be a "living wage?" No, but it will be less predatory than the alternative. To have a vibrant middle class in a developed economy, the middle class needs economic power and economic protection. The limits of that power and protection are of course subject to reasonable debate, but eliminating the minimum wage would likely be a disaster for the middle class, and would almost certainly be a disaster for those people who are barely making it as it is.