Sales tax is regressive and thus should not be the main source of tax revenue, we cannot push this burden onto the shoulders of people who already have the least.

I think we currently suffer from a tax system that enables double-taxation by default - unless you're fairly good filing your taxes and know where to claim deductions. My parents raised me to be knowledgeable of what's a work expense, and things have gotten easier with Turbo Tax - but it still surprises me how many of my friends and relatives file a 1040EZ.

Personally I think it's strange that we start at 10% income tax on people making so little.

You're technically correct, though I've found regressive always makes it sound like poor people pay more, when in reality poor people pay less.

Anyway, most high sales tax proposals come with a post capita rebate.