Kevin Drum: "Most Americans just aren't willing to do backbreaking agricultural labor for a bit above minimum wage, and if the wage rate were much higher the farms would no longer be competitive."

Well... competitive with who? I'm absolutely pro-immigration reform, but i've always had a problem with this "they do the work we won't" argument, and you can see the sleight of hand between Drum's post title and his conclusion, which slips in the "for a bit above minimum wage". The real argument is "they allow our food prices to be cheaper than they should be" which is potentially still a good argument but now you're getting into a NAFTA style "Walmart's low prices vs. overseas sweatshops and American jobs" argument.