The necessities of life occasion the great expence of the poor. They find it difficult to get food, and the greater part of their little revenue is spent in getting it. The luxuries and vanities of life occasion the principal expence of the rich; and a magnificent house embellishes and sets off to the best advantage all the other luxuries and vanities which they possess. A tax upon house-rents, therefore, would in general fall heaviest upon the rich; and in this sort of inequality there would not, perhaps, be any thing very unreasonable. It is not very unreasonable that the rich should contribute to the public expence, not only in proportion to their revenue, but something more than in that proportion.
Adam Smith, Wealth of Nations (1776).
So Romney with his 13% tax rate and Ryan with his proposed regressive tax cuts, are trying to reopen the debate on progressive income taxation. I feel like this debate was adequately settled a very long time ago. Why are we re-opening 18th century debates? Was the 19th century just too radically progressive?