What likely GOP candidates are conservatives?
Romney's the only conservative in the race right now who's got a real shot. I'm guessing someone will come out of nowhere, ala GWB in 2000, but that someone has yet to appear.
(And before you whip out the "Romney's a RINO pretending to be a conservative" stuff, keep in mind two things: one, the source of Romney's alleged RINOism is the Boston Globe; and two, Ronald Reagan was once a Democrat. Not that I'm saying Romney is the next Reagan, just that it is quite possible for someone's viewpoints to shift over time.)