Feinstein's amendment to an economic development bill -- which would kill a 45-cent credit for every gallon of ethanol blended with gasoline -- was the same legislation as a bill she co-sponsored with Sen. Tom Coburn, R-Okla., that was opposed by Corn Belt legislators, The Hill said.
Thursday's vote to end the tax credit -- as well as a 54-cent-per-gallon import tariff on imported ethanol -- was 73-27.
Lawmakers supporting an end to the industry's tax subsidies called incentives for food-to-fuel programs unnecessary, wasteful and expensive.
The Government Accountability Office estimates tax credits for the mostly corn-derived alternative fuel cost the Treasury $5.4 billion in 2010, The Hill noted.
The White House said it would prefer to reduce the subsidy rather than eliminate it.
"Well, we oppose the full repeal of that subsidy, but as you know, we are focused and have been focused on a broad strategy including increasing domestic development of oil and gas but also aggressive development of alternative fuels including biofuels, and also improving our efficiency, our fuel efficiency," White House spokesman Jay Carney told reporters. "And as part of our overall strategy, we would like to see reform that would reduce costs in terms of the subsidy in question here, but not -- we were not -- we did not support the full repeal."