Jonah Goldberg‘s latest column at National Review Online tackles the notion that a president and his advisers can oversee the American economy.

The idea that presidents “run” the economy is both ludicrous and fairly novel. Before the New Deal (which in my opinion prolonged the Great Depression), the notion that presidents should or could grow the economy was outlandish. But, as the historian H. W. Brands has argued, it was JFK who really cemented the idea that the president is the project manager for a team of technicians who create economic prosperity. “Most of the problems . . . that we now face, are technical problems, are administrative problems,” he explained, and should be kept as far away from partisan politics as possible.

President Obama, a hybrid reincarnation of Kennedy and Roosevelt according to his fans, came into office with similar misconceptions. Controlling the White House, the House, and the Senate, his team of propeller-heads insisted that if we passed exactly the stimulus they wanted, the unemployment rate would top out at 8 percent and would be well below that by now.

They waved around charts and graphs “proving” they were right, like self-declared messiahs insisting they are to be followed because the prophecies they wrote themselves say so.

They got their stimulus. They were wrong.

They say in their defense that’s because the downturn was so much worse than anyone realized. Okay, but that just demonstrates the folly of their confidence in the first place. If I jump off a building because I am sure I can fly (“I wrote a study that proves it!”), it’s of little solace, and even less of an excuse, if I sputter out my last words from the bloodied pavement, “The pull of gravity was so much worse than I realized.”