As If There Really Was Much Difference
"shouldn’t the papers this morning be full of retrospectives about The Event That Ended The Economy As We Knew It? (Not to mention the event that guaranteed an Obama election win.)"
While the Lehman crash did cause a temporary acceleration in the pace of economic contraction, the underlying cause of the problems can be dated to several years earlier.
But in one sense, Krugman is unintentionally more right than he realizes. The Lehman crash and the panic that ensued probably did on the margin push the election to Obama's favor (in the two weeks before the crash, McCain lead in the polls). That has in turn pushed America significantly on the path of socialism, with the partial government take over of health care, the increased power over the financial sector, the dramatic increase in government spending and government debt and higher taxes.
Though it may be hyperbole to characterize this as "Ending The Economy As We Knew It", it has represented a significant and probably largely permanent change in the statist direction