As a liberal American, my thesis is that the Republican party is extremely fractured between fiscal conservatives (who are largely centrist or even liberal on social issues) and the straight-up social conservatives. Which means that finding a single individual who can coherently represent all of them is basically impossible.
So enter Romney, who seemed willing to be mercurial - literally adopting different positions in front of different audiences and scoffing whenever anybody pointed it out. But that cynical strategy was necessary to have any viability whatsoever in such a diverse party.
>"Which means that finding a single individual who can coherently represent all of them is basically impossible."
And by the time the Republican nomination was over, the strength of the social conservatives had dragged the rhetoric so far right that it was difficult for Romney to get back to the centre for the election.
These two comments very completely and eloquently sum up the problem. The divide between social and fiscal conservatism is something that gives the republican party the biggest disadvantage.
I should also mention that the big-L Libertarians, as instantiated in the U.S., are not the fiscally-conservative socially-liberal party that centrists would even entertain. They're far too radical to be at all politically viable (abolish Fed and Education, open borders, legalize drugs, etc.).
So enter Romney, who seemed willing to be mercurial - literally adopting different positions in front of different audiences and scoffing whenever anybody pointed it out. But that cynical strategy was necessary to have any viability whatsoever in such a diverse party.