While Coburn's language would completely eliminate the subsidy, the pro-ethanol proposal would cut off the subsidy on July 1, and replace it with a variable subsidy that fluctuates with the price of oil. Proponents of the bill, like Sen. Richard Lugar (R-Ind.), said the variable subsidy bill would help guard against attempts by oil producers to lower the price of oil in order to drive the ethanol industry out of business.

"The proposal acts as a safety net to prevent OPEC from manipulating oil prices to kill off their ethanol rival," Lugar said. "When oil prices are high, as they are today, corn-based ethanol would not receive subsidy payments."

Under this proposal, ethanol blenders would get no subsidy at all when oil prices are above $90 a barrel. If oil falls to between $80 and $90 a barrel, they would get a six cents per gallon subsidy. Another six cents would be added for each $10 drop in the price of oil, and a maximum subsidy of 30 cents a gallon could be received when oil falls to $50 a barrel or less (a summary of the bill is here).

That's still less than the current 45 cents a gallon subsidy that ethanol blenders receive currently, regardless of the price of oil.

Proponents of the bill say ending the current system on July 1 and moving to a variable subsidy would save $2.5 billion. In a nod to Coburn and his supporters, the bill would use $1 billion of that for deficit reduction.

The rest would be used for the variable subsidy, but also for the development of ethanol infrastructure and other incentives. For example, the bill would expand tax credits to ethanol blender pumps, and extend through 2014 the small producer ethanol credit.

The bill is sponsored by Sen. John ThuneJohn Randolph ThuneDemocrats press for action on election security Prospects for Trump gun deal grow dimmer Trump, lawmakers consider app that would conduct background checks: report MORE (R-SD), who said Monday that senators should oppose Coburn's attempt to immediately cut off all subsidies to ethanol without warning.

"What the amendment our colleagues are trying to get a vote on tomorrow would do is basically to say to this industry: Yes, we are going to take away this particular tax incentive, and we are going to do it right in the middle of the year," Thune said. "We are going to do it, and we do not like this industry -- which is probably what animates a lot of the opposition to this because if people look at the facts, if they look at the contribution that biofuels have made to our fuel supply in this country, it is significant."

"This bill would transition to a more sustainable model of support for renewable fuel production in America instead of pulling the rug out from under an industry, with 4 days' notice, that employs hundreds of thousands of people in this country, as well as provides an alternative to oil," said Sen. Amy KlobucharAmy Jean KlobucharMark Mellman: The most important moment in history? Democrats press for action on election security Antitrust enforcers in turf war over Big Tech MORE (D-Minn.), another sponsor.

Other sponsors are Sens. Dan CoatsDaniel (Dan) Ray CoatsTrump has named more ex-lobbyists to Cabinet in 3 years than Obama, Bush did in full terms: report Hillicon Valley: FCC approves Nexstar-Tribune merger | Top Democrat seeks answers on security of biometric data | 2020 Democrats take on Chinese IP theft | How Google, Facebook probes are testing century-old antitrust laws Congress should defy Dan Coats' last request on phone surveillance MORE (R-Ind.), Richard DurbinRichard (Dick) Joseph DurbinKavanaugh impeachment push hits Capitol buzz saw Democrats seize Senate floor to protest gun inaction: 'Put up or shut up' Pressley on Kavanaugh impeachment: 'Deeply disturbing' that a justice 'could have this many allegations' MORE (D-Ill.), Al FrankenAlan (Al) Stuart FrankenThe Hill's Morning Report - What is Trump's next move on Iran? The Memo: Times correction gives GOP lifeline in latest Kavanaugh controversy Politicon announces lineup including Comey, Hannity, Priebus MORE (D-Minn.), Charles GrassleyCharles (Chuck) Ernest GrassleyWe've lost sight of the real scandal Grassley: Kavanaugh classmate didn't contact Senate panel State Dept sent explosive-detection dogs to Jordan despite evidence of mistreatment: report MORE (R-Iowa), Tom HarkinThomas (Tom) Richard HarkinWisconsin lawmaker gets buzz-cut after vowing not to cut hair until sign language bill passed Democratic debates kick off Iowa summer sprint Key endorsements: A who's who in early states MORE (D-Iowa), John HoevenJohn Henry HoevenBottom Line Poll: McConnell is most unpopular senator McConnell ups pressure on White House to get a budget deal MORE (R-ND), Mike JohannsMichael (Mike) Owen JohannsMeet the Democratic sleeper candidate gunning for Senate in Nebraska Farmers, tax incentives can ease the pain of a smaller farm bill Lobbying World MORE (R-Neb.), Tim JohnsonTimothy (Tim) Peter JohnsonTrump faces tough path to Fannie Mae, Freddie Mac overhaul Several hurt when truck runs into minimum wage protesters in Michigan Senate GOP rejects Trump’s call to go big on gun legislation MORE (D-SD), Mark KirkMark Steven Kirk The 13 Republicans needed to pass gun-control legislation Advocates push for EpiPens on flights after college student's mid-flight allergic reaction Funding the fight against polio MORE (R-Ill.), Claire McCaskillClaire Conner McCaskillEx-CIA chief worries campaigns falling short on cybersecurity Ocasio-Cortez blasts NYT editor for suggesting Tlaib, Omar aren't representative of Midwest Trump nominees meet fiercest opposition from Warren, Sanders, Gillibrand MORE (D-Mo.), Jerry MoranGerald (Jerry) MoranPompeo pressed on possible Senate run by Kansas media Jerry Moran: 'I wouldn't be surprised' if Pompeo ran for Senate in Kansas Senators introduce bill aimed at protecting Olympic athletes in response to abuse scandals MORE (R-Kan.) and Ben Nelson (D-Neb.).