"There are plenty of poor families and middle class families who don't pay any federal tax right now, who would now start paying federal tax."
Not true. They all still pay payroll taxes, 7.65% for the employee's share and 7.65% for the employer's share. Most economists believe the employer's share is taken out of the meployee's paycheck, so in essence they're already paying 15%. The FairTax also gives a rebate to EVERY American family for enough taxes to spend up to the poverty line. The closer you are to the poverty line, the lower your effective tax rate. If you're belwo the poverty line, you have a negative tax rate.
When the commercials start telling the public that their food and clothing are going to be taxed, they're going to bolt. Yes, I understand that there's plenty of tax already built in to the price of anything, but the public will choose to go with the devil they know. I think this is an electoral nightmare for the Republicans.
I don't mind making the federal income tax less progressive, but making federal taxation regressive is going to lose elections.