Why are republican donors so surprised that Romney didn't tell them the truth?
After all, they knew Romney was a "good" liar - he about Obama's positions and statements. The donors must have thought hey, if Romney can lie about Obama, what makes me think he is telling me the truth about anything?
Romney says whatever he thinks the other side wants to hear. Truth and lies have no meaning in Romney's universe. His only concern is whether his utterances will get him the results he prefers. If he could only fake sincerity as well as Reagan, then he might have amounted to something in the real world (where there are entities besides money and objectives besides getting more money).
Let me clarify that I think Reagan was only sincere as a method actor. If Reagan had been a first rate actor, then he would actually have been less plausible in his role as president. As a simpleminded but competent enough method actor, I think Reagan was quite sincere in believing whatever he saw on his teleprompter.
Romney is much more in Nixon's mold. He is smart enough to know the truth. He just doesn't care. (To be contrasted with Dubya, who never knew and never cared.)