The United States could urgently use food policy reform. Right now, we have a lot of subsidies to food growers. That’s questionable economics. But what’s more, we subsidize people to grow food that’s bad for public healthy in ways that are environmentally unsound. That’s terrible. If we’re going to subsidize farming, we ought to be subsidizing people for growing healthy crops in a sustainable way. On the merits, this is a no-brainer — there’s obviously no public interest in taxpayer subsidies for high-fructose corn syrup — but the politics is another matter.
He then goes on to discuss the particular politics of it, but I'll stick with the opening sentiment first. It really is a much better idea for so, so many reasons that if the Federal government has to be in the business of subsidizing agriculture - and there's a pretty good argument that this is the case - then it should be doing so in a way that encourages people to eat healthier rather than less-healthy foods. Yglesias points out that while it's all well and good for, e.g., Oregon's farmers to grow for local farmer's markets, the geography of Iowa - lots and lots of amazing land, not that many people - means it couldn't do the same. Which is true enough. But we don't have to go that far: even if we keep subsidies at current levels, subsidizing Iowa's farmers to grow a healthy mix of crops rather than all-corn, all-the-time would be a better way to go. Because we don't eat that corn: it goes into feed, mostly, and then some ethanol. And the feed goes into artificially-cheap-and-abundant meat - beef, primarily - which then goes into your colon and gives you cancer. Or just heart disease!
But, at any rate - the thing about subsidies is that they make it pretty easy to convince farmers to switch production: just make sure to guarantee that they'll get as much (or more) money for gorwing Crop X rather than corn, and they're good to go. There's no real sentimental attachment to millions of acres of feed- and ethanol-corn. And what would we do with all this stuff? Well, you know who needs lots of food, and food that it would be better to have healthy than not? Kids. And as the Federal government is already pretty deep into the business of school food and nutrition, it would not be a huge leap for them to become the facilitator/buyer of first and last resort for a lot of crops, which would then be directed to healthy school lunches. As a bonus, Federal subsidies of all school food could then have the effect of keeping expenses lower for school districts around the country, and of course the long-term public health benefits of kids eating a healthier, more diverse diet would be enormous.