Looking back, Romney was consistently lagging in the polls. The first problem was that he has spent his life being moderate, but running in a highly ideological primary he had to reinvent himself as 'severe conservative'. I don't think the far right ever bought it, but he steamrolled over them with huge amounts of money, so at the end of the day they had to grudgingly accept him.
He had always polled as having best chances against Obama, so the Obama campaign had long expected that race and were preparing for well over a year. And that campaign is as skillful as Karl Rove's ones (4 years ago they beat the Clinton machine, then the republicans). So, as soon as the primaries were over, they spent huge amounts of money to 'define' Romney as an out of touch plutocrat facing virtually no pushback. The whole tax return thing was ridiculous - I always thought Romney should just release them and take whatever temporary hit from low tax rates and offshore accounts, just so that it could be put behind.
The first time Romney looked viable was after that first debate when he reversed back to moderate talk. Interestingly, the conservative base suddenly got all fired up by the taste of victory, so I think Romney played that part brilliantly. He really had to deal with a pretty tricky situation - he had to be moderate to pick enough votes from the center, and at the same time keep the hyper ideological base enthusiastic.
He even managed to get the evangelicals to burry the hatchet and line up behind somebody whose religion they had labeled a cult (apparently not anymore).
I think even though he ended up a tad short, he still did amazingly well. No candidate is perfect, and he just isn't good at connecting with voters which couldn't change, but my thinking is that had he not left the Obama campaign to write the narrative for so long at the beginning he would've pulled it out. Everybody makes gaffes, the ones that have an effect tend to be the ones that 'fit' the larger narrative.
But again, after the first debate he got a pretty good bump, so if the economy didn't show good signs that may have been enough. After all that was the central premise of the Romney campaign - the economy is getting worse and worse due to Obama, hence he had to go.
:shrug: