Having FICA and Medicare withheld from a paycheck is not the same as paying Federal Income tax. Those taxes are paid regardless how much someone makes. You do not get those monies returned to you when you file your Federal taxes. Same with sales tax. Technically everyone that works or shops pays some taxes. The issue is percentage of pay that goes to the Federal Gov't just for the privledge of working legally.
The people I hear complain the most about the rich not being taxed enough are those that pay no Federal Income Tax. Those that paid in $2500, then when they file their taxes the get a $4000 refund because they are married, have kids, a home mortgage, etc. Regardless how much you make you should still pay into the Federal Tax system. They use the interstates, Pell Grants, post office, enjoy the safety the military provides, etc as much as everyone else does.
I fail to understand why many people think they are entitled to so much with little to no effort on their part. I learned in Civics class we are guaranteed Life, Liberty, and the Pursuit of Happiness. Not a house, medical insurance, a free college education, a new Smart phone every 6 months, or an upper level management job straight out of college.