It's not hard to think of things more important than the Dow Jones Industrial Average. Odds are you're thinking of one right now.

The stock market, after all, isn't the best barometer of the economy's health. And the Dow isn't even the best barometer of the stock market, since it averages share prices in a weird way. But if arbitrary round numbers are your thing, the Dow passed a big one on Tuesday, closing above 18,000 for the first time.

And that brings us to the worst op-ed in history. On March 6, 2009, former George W. Bush adviser Michael Boskin offered whatever the opposite of a prophecy is when he said that "Obama's Radicalism Is Killing the Dow." Now let's set the scene. Obama had been in office for less than two months at that point, and in that time, stocks had admittedly fallen a lot as markets worried that the big bank bailout known as TARP wouldn't actually be enough to save the banks. It got so bad that Citigroup briefly became a penny stock.

Boskin, though, didn't think that this once-in-three-generations financial crisis was to blame for the market meltdown. Instead, he blamed it on Obama for ... talking about raising taxes? "It's hard not to see the continued sell-off on Wall Street and the growing fear on Main Street," Boskin philosophized, "as a product, at least in part, of the realization that our new president's policies are designed to radically re-engineer the market-based U.S. economy." What followed was the usual conservative jeremiad against higher taxes on the rich, lower taxes on the poor, and deficit spending. Obama's trying to turn us into Europe, and that's why markets are pricing in the possibility of a Great Depression—not the dying economy he inherited.

It was an obvious stretch, but it was extraordinarily ill-timed, too. You can see just how much in the chart below.

Stocks bottomed on March 9, three days after the op-ed, as the Federal Reserve's bond-buying and the Treasury's stress tests restored confidence in the financial system. Then the stimulus started to kick in, putting enough of a floor under the economy that it began growing again that summer. It's been a nasty, brutish, and long recovery, but unemployment is finally back under 6 percent and the economy is now growing at its fastest pace in over a decade.

Add it all up, and Obama's radicalism has killed the Dow to the tune of a 171 percent return since Boskin's op-ed.