I'm late (again) mentioning this, but Steve Benen at The Washington Monthly (one of the best political bloggers going) posted something June 25 that seriously deserves to be read.
In it, Benen points out that prominent conservatives have a remarkably consistent record of making economic projections that are later seen to be spectacularly wrong. The full article goes into more detail and quotes some now-amusing wildly wrong forecasts of doom, but here is the short version.
In 1982, Reagan raised taxes and the right assured Americans this would be a disaster. The right was wrong, and the economy boomed.
In 1993, Clinton raised taxes and the right was even more certain this would be a disaster. The right was wrong again, and we instead saw the longest and strongest sustained recovery in recent memory. [Update: This is actually an understatement; in fact, the expansion in question was the longest in American economic history.]
In 2001, Bush slashed taxes and the right swore up and down this would work wonders. The right was wrong again, and the Bush policy failed spectacularly in every possible way.
In 2009, Obama spent heavily to turn the economy around and the right predicted a disaster. The right was wrong, and conditions improved almost immediately. The economy that had been in a tailspin, hemorrhaging jobs, began growing and creating jobs.
"How do Republicans explain this?" Benen asks. "That’s not a rhetorical question. I seriously want to know how and why they believe their uninterrupted track record of failure should be overlooked."