Michael Kranish's December 23, Sunday Globe article "The candidate who never really let voters in" link here or below analyzed many aspects of the Romney campaign that failed and allowed the president a commanding victory and Romney a stunning loss. The blame ranged from people who controlled his campaign, the GOP primaries that hurt the candidate himself, to the over abundant minority vote and less abundant white vote.
Romney's son Tagg's revealing that Romney wanted the presidency less than any other was perhaps the most stunning admission of all. If true that served to reinforce for me that the REAL blame for Romney's loss is that Romney tried to fit a round peg into a square hole. I believe it was not Romney the man but Romney the snake oil salesman he was commanded to be by the Republican base which demanded radical right ideological purity that lost the election for him. Romney had to cast aside groups which in Massachusetts he courted -- women, pro-choice voters and gays. Heck he even sent an emissary to the gay pride parade in Massachusetts when he was running for governor. It was not Mitt Romney himself who lost the election but the Romney base that lost it for him as it demanded something which was not who he was. When he and others are finally nominated by Republican base and need to run nationally they lose.
The nation is centrist in nature sometimes a little right and sometimes a little left but what they are NOT is extreme. No matter how good the Republican bench is their candidates may lie to appeal to the Republican base but the lie of who they are is not lost by the general electorate and they reject it. Republicans if they do not carve out a better brand -- which they seem not inclined to do -- will lose every time!