Where are the mid-size farms?

In an article from Grist, Hole in the Middle, Tom Philpott suggests that the insignificance of real sustainable food available in the US is due to a lack of a market for mid-size farms, that could conceivably provide a reasonable amount of food that small farms simply cannot produce. This was an interesting article, but I wish the author had speculated more about how to possibly create this market that was an alternative between farmer's markets and corporate national grocery chains. He suggested that local movements are the main efforts attempting to salvage these farms. Because the mid-size farms already lose money on the production of their food crops, they do not have the means to invest in restaurants etc. What if there were governmental policies that supported these farms instead of massively subsidizing corn, depleting any revenue for mid-scale farmers?

Thank you Zach S. for the article.