Chuck Gray, the winger state senator from East Mesa (with Russell Pearce covering West Mesa, Mesa is represented in the State Senate by all sorts of nutty), has announced that he won't be running for re-election next year in order to pursue as yet unspecified "business opportunities."
Not being a Republican, much less an East Mesa Republican, I don't have any insight into who is going to step forward as candidates to replace Gray as the third member of the R slate in LD19. However, my best guess is that they will be contending for a House seat, as State Rep. Rich Crandall will probably try to move over to the Senate.
He was rumored to be interested in the Superintendent of Public Instruction spot, but that primary is already a cattle call on the Republican side (five candidate committees and counting). In addition to that, Crandall's seatmate in the House is Republican Kirk Adams, the Speaker of the House.
Something tells me that Adams isn't likely to want to go from the top position in one chamber to a rank-and-file position in the other (OK, assuming he successfully made the transition, he'd probably rate at least a committee chair). At least, not until he is forced to do so by term limits.
As such, Crandall seems likely to be the one to try to move to the Senate, possibly to help set up a statewide run of some sort in 2014.
Look for more such announcements, from both sides of the aisle and in both chambers, as the turn of the year approaches.