@spendius,
Not sure what you're referring to as the excuse.... his Mormanism? Or, discerning nuances in his presentation? Something else? dunno...
Religion in voting practices run very deep here. There are folks who wouldn't dream of voting for a non-Christian (and that gets more and more narrowly defined as you get closer and closer to those who would choose based on that), others who wouldn't dream of voting for a theocrat <raises hand>, and others who would vote for anyone except a Jew, or a Catholic, or an atheist, or.... the list goes on and on, each with a subset of folks who think a particular religious belief disqualifies someone from the Presidency.
I think Gingrich is currently the darling of the "anyone but Romney" crowd (sometimes called "the base"). The problem there is that main-stream Republicans ("the core") don't want him to be the candidate. The Republican party is in the process of imploding. There are those who are calling for a brokered convention so that "none of the above" gets named at the convention and someone else entirely gets chosen to run in the general election. It's a very interesting dynamic.