John Dickerson has a great piece explaining how Team Romney ended up so surprised at their defeat even though national public opinion surveys showed he would probably lose and state polling showed that even more clearly. I don't think we can completely rule out the story that GOP operatives are just engaging a massive campaign of post-election lying right now, but they probably aren't. (Big conspiracies are hard to organize.) And if they're not, it should give us some doubts about their party's policy acumen.
The key reason is that their misanalysis betrays a stunningly weak grasp of social science. And mastering the social sciences is the key to actual policymaking, not just election forecasting. Here's Dickerson:
The Romney campaign thought Obama’s base had lost its affection for its candidate. They believed Obama would win only if he won over independent voters. So Romney focused on independents and the economy, which was their key issue. The Republican ground game was focused on winning those voters. “We thought the only way to win was doing well with independents and we were kicking ass with independents,” says a top aide. One senior adviser bet me that if Obama won Ohio, he would donate $1,000 for every point that Romney won independents to my favorite charity. (That would be a $10,000 hit since Romney lost Ohio but won independents by 10 points). In the end, Romney won independents nationally by five points—and it didn’t matter one bit.
That it'll all come down to independents is a very solid, common-sense analysis of the situation. But it's wrong. The evidence is really overwhelming that partisan self-identification is much more an attitudinal variable than a demographic one. In other words, it's unstable. As the political winds shift, people's self-identification shifts along with it. But their voting behavior doesn't shift nearly as much. So if for one reason or another—George W. Bush's unpopularity, House Republicans' irresponsibility over the debt ceiling, etc.—the Republican Party brand gets damaged, many white Christians over the age of 30 will start identifying as independents rather than Republicans. But these people are still conservative people who don't want to vote for a tax-hiking, abortion-loving environmentalist. So as conservatives shift out of GOP identification and into independent identification, it becomes easier for Romney to "win independents" without it becoming any easier for him to win the election.
That said, the GOP analysis of the situation really is in line with common sense. It's just wrong. And the majority of polling operations, along with everyone who's studied the issue in academia, knew that it was wrong. Common sense just turns out to be a poor guide to a lot of complicated social phenomena.
Unfortunately, this matters for the country substantively because this kind of expert analysis is also important to substantive policymaking. Now let me be clear—nobody likes it when the experts tell them that their preconceptions are wrong. Everyone makes this error. Some liberals do it on genetically modified foods, others do it on tax preferences for investment income. But it is also true that, sociologically speaking, being on the same side as expert opinion is a high-status concept inside liberal and Democratic Party circles. This sociological embrace of expertise acts to temper the psychological mechanism of confirmation bias. On the right, the idea of academic expertise is held in low esteem. Conservatives accurately perceive that academia is hostile to nationalism and religious traditionalism and thus become much more prone to become out of touch with academic knowledge or to reject valid academic insights even on other topics. The same mechanism that can make you clueless about the meaning of "independent" self-identification can also lead to dangerously misleading public policy conclusions. Common sense and going with your gut are a poor way to understand the world.