Sugar cane makes better ethanol than either, but they don’t row it where it will do either party any political good.
Better? no. Just more expensive.
THE ECONOMIC FEASIBILITY OF ETHANOL PRODUCTION FROM SUGAR IN THE UNITED STATES
http://www.usda.gov/oce/EthanolSugarFeasibilityReport3.pdf
USDA July 2006, see page iv
U.S. Corn wet milling = 1.03
U.S. Corn dry milling = 1.05
U.S. Sugar cane = 2.40
U.S. Sugar beets = 2.35
U.S. Molasses = 1.27
U.S. Raw sugar = 3.48
U.S. Refined sugar = 3.97
Brazil Sugar Cane = 0.81
E.U. Sugar Beets = 2.89
All in dollars per gallon