The tax RATE should be equal, not the dollar amount. I would suggest that you spend some time reading about the plan and the philosophy behind it.
Can you tell me of a plan in congress that has support that works better than this one?
The hell with rates, equal citizens should get equal bills. Say two guys get the same pay rate. one sacrifices and works Saturdays and the other does not. I say they should get the same tax bill and any extra the Saturday worker earns the government has no claim to. You by supporting a rate, keep the government punishing the extra effort. I say an equal tax amount is fair, because it doesn't punish someone for being more productive, it frees people from taxes once they have paid their bill.