The issue was what most called Romney's record of "creative destruction" (Romney's preferred term as well) while working at Bain. Romney successfully eliminated inefficiencies, turned failing companies into successful ones, and also let (made?) companies that were clunkers fail. Romney had previously played on his private sector success as an asset in an election that might come down the economy: this is particularly true when you consider that Romney, as a conservative governor in a very blue state, had to make a number of concessions on liberal issues (health care, gay rights) that wouldn't play particularly well to a base still in the mood for a candidate who could not just mildly differentiate themself from Barack Obama but define themself in an entirely oppositional way. This means that Romney's record in the private sector is absolutely a key linchpin for his campaign: in order to compare himself to Obama, long a man of the public sector, Romney needs to be able to wield a mantle of expertise on all matters economic, based mostly on him "having really done it" while Obama stood on the political sidelines and mettled.
I doubt sincerely whether the facts of Romney's tenure at Bain will much matter for messaging purposes in either the Republican primary (which, btw, Romney will probably still win handily. For the love of God, Newt freaking Gingrich?) or the general election. And I mean that in the following sense: even if the "fact" is that Romney made companies leaner and freed up inefficiencies to both redistribute workers and create more profits (that then flow back into the economy) Romney's narrative will have to first have an awkward encounter with the obverse side of the American dream: that for all the winners in America, there are losers, too, and those losers might either not want to confront their status as such, or might be losers only by virtue of some factor beyond their control (rather than say, their lack of fitness or capacity for certain sorts of work).
To really understand why this matters, we need to go back to the Spring of 2008, when the economy was facing a difficult time, and Phil Gramm said openly that America, during tough economic times, had become "a nation of whiners." Immediately afterward Gramm, who had been a campaign surrogate and adviser for John McCain, took a less visible role in McCain's campaign after withering criticism from pundits, journalists, and ordinary Americans who understood their own dwindling economic prospects as something real, and not just part of a "mental recession." Of course, Gramm wasn't that wrong about the "mental recession" claim: conservatives and liberals alike tend to agree that attitudes (read: consumer confidence) impact the REAL measure of an economy's strength i.e. optimism, willingness to invest given the promise of profit, etc. This didn't matter: by calling those who were struggling "whiners" Gramm tapped into a fear that the typical discourses of liberal individualism in America are effective at displacing: the fear that one might just not be good enough.
After all, Americans are coached that they are special, unique, and exceptional folks, gifted with talents and powers that will help them get to a place of real material and spiritual success. We can find evidence of this either in advertisements (which often hold that the simple capacity to choose the right product makes us special), political discourses (show me a politician who has publicly disavowed the American Dream, and I will show you a non-entity. Moreover, this dream is accomplished by hard work and the application of ingenuity, rather than positioned as an effect of a combination of talent and luck), and plucky cultural narratives about overcoming adversity (Ragged Dick, or choose your superhero). Financial and personal success is an index of one's talent and agency. This accords with how exceptionalist narratives work: if we achieve our City on a Hill through a combination of hard work and good luck, there is nothing to distinguish us from others who work hard other than some kind of beneficial cosmic fortune. On the other hand, if we own that City on a Hill because we mixed our labor with it, it is ours.
This is different from the account of virtue Aristotle gives in the Politics, where talent and hard work are not enough. Chance is preserved as an element contributing to greatness: with talent and hard work but bad luck, one is simply not great. Now this initially seems harsh, but on a second blush it provides a rather appealing account for how to judge success because it installs a kind of ontological humility upon those who succeed: they are never as great as their successes, but they are also (presuming they work hard) never as bad as their failures.
What does it mean, then, for politics to take place on a plane where chance has been eviscerated in favor of an omnicompetent liberal subject who is all knowing, all seeing, and all succeeding? Firstly, it means that those who have not succeeded will struggle to be understood as victims of chance or bad fortune: instead, their status as less materially successful will be read as an index of their competence and effectiveness as a human. (Think of the health care patient facing death lustily booed during an early GOP primary debate: this only makes sense if they are facing a fate they earned). Second, this acts to determine in advance how individuals are understood in a way that tautologically secures one's position in the social hierarchy: not being well off indicates you lack that special something. Instead of the possibility that you have encountered challenges and failed to defeat them, challenges are denaturalized, and thought to collapse easily upon the power of AMERICAN INDIVIDUAL HARDWORKING MCAWESOMEPERSON.
When Phil Gramm complains that America has become a nation of whiners, it is exactly the last thing that anyone who is poor off wants to hear. After all, they've been coached and told and encouraged to think that they are special, talented, and that if they just worked hard things would work out. And yet sometimes, they don't. Without chance, we get a nation of whiners instead of nation of folks facing some hard luck. Without chance, we understand a health care bill that rewards people who have bad market acumen. Without chance, we understand a social safety net to be a form of social Darwinism rather than insurance against fortune's worst.
But without chance, Romney's acumen at diagnosing businesses' flaws and inefficiencies enables him to straightforwardly personify the reasoned decisions that displace many within the economy. Quick reminder: subjectivity works through processes of negative definition and scapegoating, rarely trending towards the positive and/or processes of mortification which humble the subject. Folks without jobs are unlikely to understand their bad situation as something which they have entirely earned themselves. One person's "inefficiencies" are another persons livelihood. If Romney's professional legacy becomes understood as personifying and embodying what the conservative principles of "increased efficiency" mean then in an election where the economy matters, his professional success will become a millstone around his neck. "Efficiency" and other such buzzwords work effectively as abstract concepts, but have a more difficult road to hoe when people can place them in a context that ensures a personal identification against them. Put it this way: you can repeat over and over that a rising tide helps all boats, but when some boats aren't doing so well, they might not give a damn about the narrative.