Peter Schiff and the Austrian School fundamentalists make claims without regard for the actual facts.
http://www.miseryindex.us/urbymonth.asp
As a case study, lets go from the beginning of 1950, where the minimum wage was 75 cents, to October of 1997 where minimum wage was 5.15. Unemployment went down from 6.5% to 4.7%. And the places in between where unemployment above above the 6.5% figure were not correlated to a minimum wage increase, but to other economic events.
It is simply a fact of physics that if a product costs more, there will be downward pressure on the demand for that product, no matter what it is. If you argue this isn’t the case for labor, then you have to argue the possibility that nothing in the economy makes sense. Hopefully you aren’t arguing that there is zero correlation between the minimum wage and the employment of teenagers, are you? Because that would be ludicrous.