In 1993, conservatives unanimously predicted that Bill Clinton's tax increase on incomes over $200,000 would slow growth, reduce tax revenues, and likely cause a recession. Instead, of course, the economy boomed and revenue skyrocketed. Then George W. Bush cut upper-bracket tax rates, and conservatives predicted that this would cause the economy to grow even faster. Instead, the economy experienced the first business cycle where income was lower at the peak of the business cycle than it had been at the peak of the previous business cycle. It is rare that events so utterly repudiate an economic theory.

None of this evidence has penetrated the conservative mind to the slightest degree. Reading the right-wing press, it is exactly as true today as it was 18 years ago that reducing Clinton-era upper-bracket tax rates holds the key to economic growth. (The latest Weekly Standard editorial: The best place to combine fiscal rectitude and pro-growth economics is the tax code. "After repealing Obama-care, the second agenda item for the new GOP Congress is extending current tax rates.")

My favorite such statement comes from Pat Toomey, current GOP Senate nominee in Pennsylvania, and former president of the Club for Growth, which lobbies for low tax rates for the rich. This is a priceless exchange:

Mr. Toomey says he favors making the Bush-era tax cuts permanent for all Americans — which would add $700 billion more to the deficit over 10 years than the plan advocated by President Obama to let the lower rates expire for the rich. But he also expresses a desire to reduce the deficit.

At the ironworks shop, Mr. Toomey brushed aside a question from a local reporter who pointed out that real income for American workers dropped after the Bush tax cuts, saying he did not believe the data.

Kind of hard to change somebody's mind when they reject the data that disproves it sight unseen.