The political class inevitably invokes the moon shot or Manhattan Project as a model for every unrealistic energy goal, but for once maybe that hyperbole is apt: A left-right coalition is emerging to end ethanol subsidies.

Last week, no fewer than 17 Senators signed a letter calling ethanol "fiscally indefensible" and "environmentally unwise." Led by Democrat Dianne Feinstein and Republican Jon Kyl, the group said Congress shouldn't extend certain subsidies that expire at the end of the year, including the 45-cent-per-gallon tax credit for blending ethanol into gasoline and tariffs on cheaper imports. Conservatives like Tom Coburn dislike this costly industrial policy, while liberals like Barbara Boxer and Sheldon Whitehouse are turning against the hefty carbon emissions that come with corn fuels.