I'm not sure it's "confused" as much as it is they underestimated the anger.
As others have noted, there are two segments of the Republican party. There is the less affluent, less educated portion that gladly supports Republican positions because in part the establishment threw them a few bones on the social issues, and in part because even though these people may be very poor, they still actually believe in the American Dream, that a person can raise themselves up to be fabulously wealthy. These people are angry. They don't like being called religious nuts or rightwingers or knuckledraggers or whatever other names the opposition or media want to drag out. They are angry because they haven't yet achieved the American Dream, personally, and believe that is due at least in part to government policies that transfer wealth to people they perceive as poor Democrats.
The more establishment portion isn't angry. They're living the American Dream. They understand that whatever is thrown to the poor as part of government social programs has relatively small impact on their own personal financial well-being. And they don't really care when people call them knuckledraggers, neanderthals, or right wing nuts. Their response to this name calling is usually just, "Ok, funny Keith, now get back to work before I decide to fire your azz."
Contrary to what Kep and others want you to believe, the anger to the Republican underbelly isn't just being stirred up by the Karl Rove's of the world to get out the vote. Those efforts are being supplemented, and even overtaken, by what has become a very caustic and attack prone society, media, social media, etc..., in which the "other side" has to not only be refuted through rational responses to their policy positions, but vilified in the most strident terms possible. The anger created by this behavior does not just disappear with an election. The hard boil may simmer down a bit, but like the Hatfields and McCoys, just sits there waiting to be stirred up again.
And this is a problem for both parties.