I made 70K last year. My total tax paid (fed, state, ss, medicare, food, gas, utilities, etc.) as a PERCENT of my income is the highest of all income levels.
When you say you made 70K, I assume you are talking gross income rather than taxable income. This would put you either in the 15% or 25% marginal tax bracket at the current (w/ GWB tax cuts) rates.
If you are married, filing jointly, with two kids, you would have $14600 in exemptions, a standard deduction of $11,400 (assuming you don’t itemize) which would make your taxable income somewhere in the neighborhood of $44,000, and your federal income tax would be $5,765 which is 13% of your taxable income, but less than 10% of your gross income. With the child tax credit the tax would even be less.
If I was wrong in my assumptions and you are single with no kids, then your standard deduction would have been $5,700 and your personal exemption would be $3,650 leaving you with taxable income of $60,650 and a federal income tax bill of $11,350 which is 18.7% of the total taxable income.
As for state, ss, medicare, gas, and utilities, those taxes are high for everybody. Unless you are eating out a lot, most food items are not taxed. So your total tax bill is not as high as a percentage of income than someone making two or even three times as much as your income since their ss and medicare taxes go up with their income, their state taxes are probably substantially higher since they will have a higher property value house with attendant higher utilities, etc.
Of course, if the Bush tax cuts are allowed to expire your marginal tax rates (at every income level) will go up and your taxes will be much higher.