> why should the Federal government finance the tax methods the states impose on their citizens The underlying assumption to your question is that the money be

> why should the Federal government finance the tax methods the states impose on their citizens The underlying assumption to your question is that the money belonged to the government in the first place. By that logic, you go to work, produce economic value, various levels of government take what they want, and you receive whatever is left at their pleasure. That's your income: whatever part they decide to let you have after they're done dividing up the money that your employer desired to pay to you. Thus by not "allowing you to deduct" taxes paid, one level of government is literally trying to tax you for money that has been taken by another before you got any of it.