For the sake of derivation/analysis, let us assume that the republican voters as a population group are not stupid/incoherent (An assumption that appears to be true, or at least there is no overwhelming reason to reject it) . In 2008, the republicans concluded that Mitt Romney is worse than McCain. Since the latter was soundly defeated by the then very inexperienced Obama, by implication Mitt Romney (according to republican voters only) would be more than soundly defeated by an even more experienced and Presidential Obama.
The above is an analysis not a prediction.
The above is an analysis not a prediction.