Or why politicians suck. Politicians from both parties support this.

. . . But politics indeed plays a large role, as Congress subsidizes favorite industries and the Federal Reserve pursues an expansive monetary policy.
. . .
What triggered the upswing? In part: ethanol. President George W. Bush “came forward with—what do you call?—the edict that we were going to mandate 36 billion gallons of alternative fuels” by 2022, of which corn-based ethanol is “a substantial part.” Companies that blend ethanol into fuel get a $5 billion annual tax credit, and there’s a tariff to keep foreign producers out of the U.S. market. Now 40% of the corn crop is “directed to ethanol, which equals the amount that’s going into livestock food,” Mr. Pope calculates.

The rapidly depreciating dollar is also sparking inflation, although Mr. Pope says that’s a “hard” topic for him to discuss, trying to be diplomatic.