Tom Coburn has sprung a plan to force the Senate to vote on the ethanol subsidy:

Sen. Tom Coburn has pulled the trigger and is forcing a long-sought vote on an amendment repealing billions in annual tax incentives for ethanol.
The Senate will vote Tuesday afternoon on Coburn’s motion limiting debate on his amendment that would do away with the 45 cent blender tax credit for ethanol — worth about $6 billion this year — and the 54 cent tariff on imported ethanol.

Wait, don't go to sleep, there's something going on here. The press coverage doesn't say so, but this is actually not about ethanol. It's about Republican anti-tax dogma.

I wrote about this a few months ago, but for those readers who haven't committed my blog to memory -- shame on you! --  I'll refresh. Nearly all Republicans have signed a Taxpayer Protection Pledge, which is enforced by Grover Norquist. The pledge forbids the signer from approving any increase in tax revenue under any circumstances whatsoever.

Coburn and a handful of Republicans are trying to get around this pledge. Their tactic is to negotiate revenue increases that take the form of closing loopholes and exemptions rather than raising rates. This would clearly violate the Pledge. But Coburn is trying to expose the silliness of the Pledge. He's holding a vote on eliminating the ethanol subsidy. Now, conservatives oppose the ethanol subsidy. But since the subsidy is a tax credit, then eliminating it is a tax increase, and forbidden by the Pledge.

So Coburn's goal here is to drive a wedge between conservative doctrine and Norquist's anti-tax dogma. If Norquist opposes a vote against ethanol, he reveals how absurd his pledge actually is. If he supports it, then he proves that it shouldn't be taken literally. Either way, it creates a talking point that Republicans could use to support revenue increases. And since the GOP's theological opposition to revenue increases has been driving budget policy for more than two decades, this is a pretty important development.