actually, the farmers will make less money because theywill grow less corn
impact on food is minimal
You fail to consider time and the perceived lag in production. The prices did rise in response to demand but in response the farmers produced more. This year, there will probably be record production in spite of the floods last spring. The production increase will mitigate the price rise earlier.
The increased production is not sustainable if ethanol subsidies are ended. Thus, farmers lose and land will produce something else or go fallow