But with a national sales tax you wouldn't be taxed at the 'employment' level, just on what you spend, thus no "AGAIN".
Unless you have savings. Then you will be taxed twice, once at the income level and again at the sales level. It's OK I guess if you are in debt, as you then get to pay off goods aquired without a sales tax with money not taxed as income, but tough luck if you have managed to save up any money for your retirement.
I am talking about the retirement money I have slaved to save to this point. I already paid tax on it when I made it and a national sales tax would tatoo me AGAIN!