Congress last week quietly passed the farm bill, a vast collage of legislation affecting the agricultural economy of the United States. This law, which Congress updates every five years, undergoes constant revision. But a few things never change. Foremost among these are the elaborate protections and subsidies given to nation’s wealthy farmers of sugarcane and sugar beets. Their ability to fend off foreign competition for nearly two centuries is a case study in the way that protectionist measures can become political economy zombies, defying all efforts to kill them off. Congress first slapped a tariff on imported sugar in 1789, but this was designed to raise revenue, not protect domestic interests. In 1842, Congress passed a new, two-tiered tariff on foreign sugar, raising rates on refined-sugar imports in the hopes of promoting domestic refiners, while a separate, but lower, tariff on raw sugar sought to protect domestic producers, mostly in Louisiana.