>Isn't a graduated flat tax a contradiction in terms?

I don't think it is. If you make under 20,000 per year, you pay 10%, if you make over 500,000 per year, you pay 30%, no deductions, no trusts, no nothing. You earn, you pay.

>And what is there about a flat tax that would eliminate loopholes and what is there about a graduated tax that encourages them?

Nothing but the flat tax. No deductions, no nothing.