I'm going to superstylize the numbers here to make a point.
A hugely common trope since the election is that the Republican Party has been permanently discredited for being optimistic in the last few days of the election, for not believing the polls that showed, on average, Obama with a 51-49 lead in the two-party vote, and for not, therefore, giving up or something. This just proves Republicans are against Science, because polling is the essence of Science and can never go wrong.
What's been overlooked is that when all the votes were added up nationally, the polls were wrong by a two point margin, just as Romney hoped. Polling is actually pretty hard to get right, and unexpected new developments can throw it off. Unfortunately for Romney, the polls' bias was in favor of Romney not against: Obama actually won 52-48.
In general, people love horse race analyses, even though it's not really very important. What was Romney supposed to do with three days left in the election? Give up?
The vastly bigger issue is that the Republicans don't understand the long term fundamentals of their electoral position: their voters represent the core of American (on multiple dimensions: married v. single, white v. nonwhite, and so forth) while the Democrats represent the various fringes. What they cannot survive is a worldview in which demonizing the core of America is the default response in the culture.