Some people were saying that evangelicals would not vote for a Mormon. It looks like that may have been true, at least to some extent.
When we found out Romney was our candidate, most of us freaked, NO WAY!! He was pro-abort, wanted carbon taxes, presided over homosexual pseudo marriages when his veto pen could have prevented them all, forced Romneycare on the people of his state, and much, much more. When he decided to run for the presidency, he buried it all.
We wanted to stop Oboma. WE sucked it up like fools and supported the Mass. liberal anyway.
Not everyone is as political as we are. They saw two terrible candidates - both liberal, and said screw it. (Especially those who pay taxes and are forced to pay for every liberal policy ever enacted. Neither candiate would have brought them noticable relief, so why bother?)