The economist shows that the principle in the politician's conclusion would lead to an inherently absurd idea. The economist uses the politician's own principle; she doesn't present a principle that contradicts the politician's conclusion.

The economist does not present this kind of evidence. Rather, the economist discusses the effects on a theoretical level. The economist does not discuss practical results of implementing the politician's advice.

The principle derived by the politician is the lower the income tax rate, the more revenue the government will generate. The limiting case is applying the politician’s principle to an instance where the income tax rate is 0 percent. The economist shows that the politician's principle leads to the absurdly false idea that an income tax rate of 0 percent would create the most income tax revenue

The economist makes no claims about the politician's knowledge of economics. Rather, the economist is simply pointing out that the politician’s principle would lead to an obviously false conclusion.

The economist does not attack a premise asserted by the politician. Rather, the economist criticizes the politician’s conclusion by pointing out an obviously false outcome. The economist does not claim that the politician's statement about a 100 percent income tax is false.