A strong candidate for the most expensive policy blunder of recent years would have to be the mandate to blend corn ethanol and other biofuels into the nation's gasoline supply. This month even the Environmental Protection Agency essentially acknowledged that the program is increasingly unworkable and costly to consumers. The EPA just won't do much to fix it.

When these mandates were enacted in 2007 under George W. Bush, biofuels were sold as the wonder-fuel of the future: a cheap and plentiful domestic energy source to compete...