If there's one thing that Republican politicians agree on, it's that slashing taxes brings the government more money. "You cut taxes, and the tax revenues increase," President Bush said in a speech last year. Keeping taxes low, Vice President Dick Cheney explained in a recent interview, "does produce more revenue for the Federal Government." Presidential candidate John McCain declared in March that "tax cuts ... as we all know, increase revenues." His rival Rudy Giuliani couldn't agree more. "I know that reducing taxes produces more revenues," he intones in a new TV ad.
If there's one thing that economists agree on,...