It is news that someone with a 100% name recognition cant break 50%. She is polling well under Obama's 2012 result.
Bush looks like a sure loser however.
I think the GOPe will dump Bush for Rubio
I don't think even incumbents who go on to win are over 50% in head-to-head polling 18 months before the election! Some voters like to reserve the right to make up their mind at the last minute, but there is no evidence they break for or against incumbents on average. Hence, the margins are what matter. The last time someone polled over 50% more than a year before the election was probably G.H.W. Bush in early 1991, and we all know what happened there.