Dan Quayle, in his acceptance speech at the 1992 Republican convention, attacked the idea of progressive taxation, in which the rich are taxed at a higher rate than the poor. His argument went like this: "Why," he asked, "should the best people be punished?" The line brought thunderous applause.
It should now be clear why, from the conservative worldview, the rich should be seen as "the best people." They are the model citizens, those who, through self-discipline and hard work, have achieved the American Dream. They have earned what they have and deserve to keep it. Because they are the best people - people whose investments create jobs and wealth for others - they should be rewarded. Taking money away is conceptualized as harm, financial harm; that is the metaphorical basis of seeing taxation as punishment. When the rich are taxed more than others for making a lot more money, they are, according to conservatives, being punished for being model citizens, for doing what, according to the American Dream, they are supposed to do.
Taxation of the rich is, to conservatives, punishment for doing what is right and succeeding at it. It is a violation of the Morality of Reward and Punishment. In the conservative worldview, the rich have earned their money and, according to the Morality of Reward and Punishment, deserve to keep it. Taxation - the forcible taking of their money from them against their will - is seen as unfair and immoral, a kind of theft. That makes the federal government a thief. Hence, a common conservative attitude toward the government: You can't trust it, since, like a thief, it's always trying to find ways to take your money.