Everyone is linking to former Reagan budget director and private equity investor David Stockman’s brutal dissection in Newsweek of Mitt Romney’s claim that his Bain years have equipped him to be a job-creating juggernaut of a president:

Mitt Romney claims that his essential qualification to be president is grounded in his 15 years as head of Bain Capital, from 1984 through early 1999. According to the campaign’s narrative, it was then that he became immersed in the toils of business enterprise, learning along the way the true secrets of how to grow the economy and create jobs. The fact that Bain’s returns reputedly averaged more than 50 percent annually during this period is purportedly proof of the case — real-world validation that Romney not only was a striking business success but also has been uniquely trained and seasoned for the task of restarting the nation’s sputtering engines of capitalism.

Except Mitt Romney was not a businessman; he was a master financial speculator who bought, sold, flipped, and stripped businesses. He did not build enterprises the old-fashioned way — out of inspiration, perspiration, and a long slog in the free market fostering a new product, service, or process of production. Instead, he spent his 15 years raising debt in prodigious amounts on Wall Street so that Bain could purchase the pots and pans and castoffs of corporate America, leverage them to the hilt, gussy them up as reborn “roll-ups,” and then deliver them back to Wall Street for resale — the faster the better.

That is the modus operandi of the leveraged-buyout business, and in an honest free-market economy, there wouldn’t be much scope for it because it creates little of economic value. But we have a rigged system—a regime of crony capitalism—where the tax code heavily favors debt and capital gains, and the central bank purposefully enables rampant speculation by propping up the price of financial assets and battering down the cost of leveraged finance. So the vast outpouring of LBOs in recent decades has been the consequence of bad policy, not the product of capitalist enterprise.

This is the case that the Obama campaign has made for months, mostly in the form of a relentless barrage of ads slamming Romney over Bain layoffs and offshoring. But Obama really needs to deliver some form of it at tomorrow’s debate. More broadly, Obama needs to figure out a way of unmasking not just Romney’s claims to job-creation prowess, but also the particulars of his five-point plan for the middle class, as a bill of goods.

This new ad from the Obama campaign shows Romney claiming it’s fair for him to pay a lower tax rate than that of many middle class taxpayers, because it will lead to economic growth. It then says: “Lower tax rates for him — than us. Is that the way to grow America?” That’s good. But the case can be made still more directly that Romney is peddling the American people flimflam that has been peddled to them before. As Ari Berman notes, Romney simply doesn’t have a plan for the short term crisis; his plan promises to create the same amount of jobs (12 million) that economists say will be created in the next four years with or without any Romney proposals. (Paul Krugman dubbed his plan “five points to nowhere.”)

Obama has to figure out a way to make all this overwhelmingly clear. He needs to explain clearly that we’ve heard all of Romney’s promises before — whether it’s the idea that tax cuts on everyone, including huge tax cuts for the richest among us, will magically lead to shared prosperity, or the idea that such cuts will trigger explosive growth that will enable them to pay for themselves, rather than explode the deficit. He needs to clearly contrast that with his own agenda for major second term change, detailing that his plans will address the profound, long term problems that threaten the economic security of the middle class, and drive home that Romney’s approach has already been revealed as a failure in that regard.

The biggest danger to Obama is that swing voters conclude that Romney is offering them something new — that he represents a fresh approach. Obama needs to kill that idea tomorrow night.