Iowa is traditionally the first stop for every presidential hopeful who is plotting a path to the White House. In early March, nearly every potential Republican candidate traveled to the Agricultural Summit in Des Moines where they were pressured by state politicians and lobbyists to support corn-based ethanol. As Iowa’s Republican Gov. Branstad cautioned, “Don’t mess with the RFS.” The RFS (Renewable Fuel Standard) mandate, passed by Congress in 2005 and updated in 2007, requires refiners to blend billions of gallons of corn ethanol and advanced cellulosic ethanol into U.S. motor fuels annually. The goal was to reduce dependence on foreign oil and create incentives for the domestic ethanol industry.