<< A few weeks ago, Mitt Romney abruptly changed his main campaign message. Before that point, he had been lambasting President Obama as a likable failure, well intentioned but sadly unable to revive the economy. When asked if Obama was a socialist, Romney would deny it outright, insisting he was merely in "over his head." But starting December 7, Romney began to paint Obama as a sinister radical who had not failed, but had succeeded all too well, in transforming the basic nature of America.

<< At the time, I thought Romney's sudden switch was a response to Newt Gingrich's sudden (and apparently short-lived) challenge from the right, positioning himself to speak more directly to the fears of a freaked-out Republican electorate. But I now think Romney's campaign has concluded that his old campaign message wasn't strong enough for the general election. Conservative columnist Kimberly Strassel has a column passing on research findings from American Crossroads, a Republican independent expenditure group. Crossroads surveyed a large number of swing voters and concluded that they couldn't beat Obama merely by portraying him as having failed:

<< << "To lock down voters in the middle, Republicans are going to have to convince them that Obama isn't just a flawed and ineffective leader, but that he has an agenda and motivations that they don't share," says Steven Law, president and CEO of Crossroads >> >> [internal links omitted]

Source:
http://nymag.com/daily/intel/2011/12/why-romney-decided-to-go-glenn-beck.html

I have not seen another presidential candidate who reinvents himself as often as Romney.