The graph begins on the left in December 2007, so Obama is elected in month 11, takes office in month 13, and the stimulus package is enacted in month 14, February 2009. But the collapse in employment continues for many months, and the recovery is anemic. So the question is... why so deep, and why so flat a recovery in hiring?
Michael Barone has the answer:
Exogenous factors explain some part of the current economic stagnation. The earthquake and tsunami in Japan caused a slowdown in manufacturing. Horrendous tornadoes did not help. Nor did bad weather, though only a few still bitterly cling to the theory that it's caused by man-made global warming.