Before you watch Jeb! Bush's bombastic new campaign ad about his record as Florida governor... sure to read Paul Krugman's column about Jeb! Bush's record in Florida:

Why, then, would Mr. Bush imagine that he is privy to secrets that have evaded everyone else?

One answer, which is actually kind of funny, is that he believes that the growth in Florida’s economy during his time as governor offers a role model for the nation as a whole. Why is that funny? Because everyone except Mr. Bush knows that, during those years, Florida was booming thanks to the mother of all housing bubbles. When the bubble burst, the state plunged into a deep slump, much worse than that in the nation as a whole. Taking the boom and the slump together, Florida’s longer-term economic performance has, if anything, been slightly worse than the national average.

The key to Mr. Bush’s record of success, then, was good political timing: He managed to leave office before the unsustainable nature of the boom he now invokes became obvious.