Okay, there are two types of taxes imposed by the states- flat tax, and income tax. The income tax, the one I prefer, is a progressive system, in which people are taxed increasing amounts based on their level of affluence. On the other hand, the flat tax is a tax system, in which you are charged a certain percentage of what you buy. This turns out being an extremely regressive system, because, while the poor usually end up having to spend the majority of their money, or even taking out loans, just to make ends meet, and therefore being taxed the full percentage, or over the full percentage, of the flat tax on their incomes- wealthy individuals do not spend a large percentage of their income and therefore are not taxed the full percentage of the flat tax.
The United States itself does not have a flat tax, and does have a national income tax. My home state, Texas, has no state income tax but has a relatively high flat tax. Americans tend to like the flat tax more than people from other areas of the world, as America is a quite conservative nation compared to other industrialized nations. However, even here it is not universally well-liked.