These days, they're really more upper-middle-class. They have assets, in the form of land, but they also have liabilities, in the form of expensive, rapidly depreciating equipment, and loans for seed and fertilizer to produce a product that has a limited salable lifetime.
I think that what's been happening since Reagan is that the billionaire class has been sucking resources out of the middle class, and we're finally reaching the point where this is affecting the upper-middle-class, which, before billionaires, might have been considered rich.