Word on the street is that Idaho School Superintendent Tom Luna could be the next governor.  Luna's success in passing his "Students Come First" education reforms have made him the subject of speculation over a 2014 run - should Gov. "Butch" Otter exit the scene.      Even if Luna has those ambitions, however, he'll have to sort it out with his friend, U.S. Rep. Raul Labrador, another potential candidate.  Something else to consider is the fact that An eventual Republican candidate must survive a closed, GOP-only primary, which likely favors conservatives like Luna and Labrador over possible rivals like, Lieutenant Gov. Brad Little or Attorney General Lawrence Wasden, both seen as moderates with an eye on Idaho's chief executive post.