U.S. Sen Ted Cruz gives a speech at the Iowa Freedom Summit in Des Moines, Iowa, on Jan. 24, 2015. (Photo by Rebecca Miller) As Ted Cruz's stock rises in Iowa, he is increasingly finding himself in the crosshairs of one of the corn-growing state's most powerful lobbies: the ethanol industry. The latest sign of that arrived Tuesday, when ethanol supporters announced an ad campaign against the Republican presidential candidate accusing him of favoring the oil industry — a major part of the economy in his home state of Texas — over farmers in the first-in-the-country caucus state. The offensive,...