There is no way to justify the progressive tax rate as fair.
I've heard many explanations, but none hold water.
Every American shares the opportunity to use the services of the government equally.
Every American should shoulder a portion of the burden in providing those services.
Let me explain what happens if you tax everyone at the same rate with zero deductions or exemptions. The poor and middle class become much poorer overnight as all of a sudden, their taxes increase by $5000 to $10,000 per year. Take $10,000 per year out of the pocket of a family earning $50,000 per year, and guess what happens next. If I have to explain it to you, then it's not worth the effort. Figure it out for yourself.
Who's fault is that?
Explain to me why some should pay so much while others pay nothing for the same services and opportunities?