I'm not sure about 2017, but THIS round of pushing E15 is specifically being done to reduce gasoline prices. It's not the corn lobby, although anyone farming corn right now is probably happy. THis is an administration realizing high gas prices and higher inflation is bad politically and costly to their party in the midterms. I'm sure a GOP administration in the same situation would try something similar.
I don't think this would be happening if the GOP was the administration. It is, of course debatable. Also, to the extent of us being in the situation, the price of corn will also go up because we import fertilizer from them (on top of the rampant inflation). So even if it were not a tiny number of stations selling E15, it wouldn't probably matter, anyway. I know I haven't seen any station where I live selling E15. But there are almost none in this area selling E0, either. I would guess 99% E10.
I checked the Concours manual again, just to confirm what I thought: "Gasoline/Alcohol Blends - Gasoline
containing up to 10% ethanol (alcohol produced from agricultural products such as corn), also known as “gasohol” is approved for use." "Never use “gasohol” with more than 10% ethanol" Sounds pretty clear. Would E15 cause any real problem with occasional use, especially if used up pretty quickly and not stored a long time? Maybe not?
Also on the topic, it says "When not operating your Kawasaki for 30 to 60 days, mix a fuel stabilizer (such as STA-BIL) with the gasoline in the fuel tank." 30 days sounds a bit silly. And it is pretty rare I ever go 60 days with the same tank of gas in the bike.
But yes, if it had happened under the GOP, indeed they would probably do the same thing. Yet the strategic stockpile won't last very long (something like 90 days of replacement of what is imported).