Well, tax the poor, and you will either make them poorer (which isn't really a good outcome in my opinion) or you have to provide them with some benefit that makes up for the tax. I'm quite sure you'll agree that taking money from the poor in tax and giving it back to them through some other program is less efficient than just leaving them alone in the first place.
As for being drafted, I'm not sure why being drafted should mean that you have to pay taxes?
As for voting, I guess we could reinstate the poll tax, keep those damn poor people from cluttering up our polling places. Or we could take it a step further: $100 to vote, and you can vote as many times as you can pay.
barfo