The original purpose of income taxes (namely to pay for WW1) was intended only to affect the wealthy.  The families earning only the median amount didn't have to pay anything.  Since payroll taxes are greater for most of the poorer US taxpayers than income taxes, why not go back to the old days.  Then, we could afford to put a $3 or $4 per gallon excise tax on gasoline and diesel, giving the trucking industry tax write-offs to compensate.