As we discussed over the weekend, regarding complaints from GOP legislators and governors over the Renewable Fuel Standard and the cost of Renewable Identification Numbers (RINS), there was a big meeting with the President today. Pressure is growing on the White House on the subject of ethanol mandates and the harmful economic impact they’re having on many states, particularly those with significant refining capabilities. On the other side of the argument are the subjects of King Corn in a few Midwest agricultural states who rely on government mandates to artificially create a demand for more and more ethanol.

According to Axios, the meeting is set to be a tense one. Trump is bringing in a number of economic and agricultural advisors, as well as Scott Pruitt from the EPA. Then there are the Senators who want to speak to him:

Why it matters: The midday meeting signals how the decade-old RFS has created fierce, politically fraught policy battles between lawmakers allied with the refining industry and a separate group carrying the mantle of midwestern farming and biofuels interests.

Who is huddling with Trump: According to the White House, expected attendees include economic adviser Gary Cohn, EPA Administrator Scott Pruitt, Agriculture Secretary Sonny Perdue, Deputy Energy Secretary Dan Brouillette, and White House legislative affairs chief Marc Short.

The senators expected are: Ted Cruz, John Cornyn, John Barrasso, Pat Toomey, Bill Cassidy, Mike Enzi, Jeff Flake, Jim Inhofe, John Kennedy, James Lankford, and Mike Lee.

Notice anyone missing from that list of senators? When it comes to Texas, Pennsylvania, Wyoming, Louisiana, Oklahoma and Utah, the gang’s all here. Conspicuously missing from the list are Iowans Chuck Grassley and Joni Ernst, who you might expect to have a vested interest in being in on this. In other words, the senators from the states which are biggest in oil and gas production and/or have the most refineries are all there to bend Trump’s ear. The folks who represent the area where all the corn is grown were somehow not on the list.

One source I spoke with suggested that the Iowa delegation is in a bit of a snit over the idea that the meeting is even taking place to being with. A spokesperson for the EPA did not respond to a request for comment.

That doesn’t mean that the opponents of the RFS have an easy task ahead of them. The White House already released a statement in advance of the meeting renewing Trump’s commitment to King Corn, but for the first time mentioned being open to ways to “effectively address the effect on refiners” and discuss the costs of compliance. Could this be the first crack in Trump’s armor on this subject?

He’s got plenty of ammunition to defend himself against the oil producing and refinings states. There were a number of goodies in the new tax bill for the oil and gas industry already and fuel stocks are rising on strong market confidence even as crude inventories are declining.

But that situation won’t last forever. There are a lot more states with a vested interest in energy production and refineries than there are bending a knee to King Corn. Yes, President Trump is keeping his campaign promises in mind, but if these Senators are suggesting potentially sagging support in far more states than just Iowa (which Trump doesn’t really need to worry about in 2020 anyway), things may eventually change for the better.