Right now, if you attempt to purchase labor for a price lower than the minimum wage, that is illegal. Interestingly, though, if you attempt to sell labor for a price lower than the minimum wage, that is not illegal. Contrast this with drugs, where both buyer and seller are at risk.
There is another comment on that blog page that points out that the minimum wage is racist. The jobs that the minimum wage eliminates are disproportionately minority jobs. Why? Well, given the fact of racist employers, the minimum wage makes it possible for them to hire their preferred white employees with no penalty. Absent the minimum wage, another employer could pay blacks a lower wage. This would let them out-compete the racist employers. While one can regret the fact that racism incents even non-racists to pay blacks less, the mechanism which naturally causes harm to racists is broken by the minimum wage law.