Mr McCain's history, which includes opposition to farm and ethanol subsidies, suggests he will oppose such pressure.
Or their grandfather was a farmer and, as in so many farm families, ethanol has meant new hope for the fading towns built on corn fields.
When Republicans ran Congress, Democrats accused them of showering billions of dollars on their own favored industries, chiefly oil, gas, utilities and farm-belt ethanol projects.
"A lot of these jobs are in rural, Republican districts," he added, citing wind farms and ethanol production, which are big in Iowa, a swing state.
Senator Charles Schumer of New York, among others, has correctly called this a giveaway to the farm states (ethanol is derived from starches, mainly corn), a potential drain on the Highway Trust Fund and a threat to clean air.
As Congress begins work on a new farm bill, ethanol companies and gasoline station owners want to expand a federal program that helps pay for pumps and other equipment needed to dispense gas with higher concentrations of ethanol.
Mr McCain has some credibility on this subject, since he voted against farm and ethanol subsidies (Mr Obama voted for both), castigated bloated Pentagon procurement and refused to ask for earmarks (funds set aside for a legislator's favourite projects).
The crop will still probably be the third-largest on record, but demand for corn to be used as animal feed on American farms, in ethanol production and for exports remains high, so supplies are expected to be tight.
And while McCain embraces trade, he's a long-standing critic of farm and ethanol policies.
It greatly expanded the application scope of Ch2-2 and its enzymes, including straw returning during intermittent period of farming besides cellulosic ethanol production at room temperature.
