The reasons for this are pure arithmetic.

Go to Census, multiply the number of people at each earning level times each earning level and you can see where the taxable pool of dollars are.

There is a reason why the Average Wage is 40K. It's not 99% of America earning $0 and 1% of America earning a gazillion dollars. It's lots of people earning ~about~ 40k.

Taxable money in the nation pools up around AWI. This is why we have a near 15% payroll tax. This is why the SS cap, at 118k, touches 86% of taxable income.

Historically, an average of roughly 83 percent of covered earnings have been subject to the payroll tax. In 1983, this figure reached 90 percent, but it has declined since then. As of 2010, about 86 percent of covered earnings fall under the tax max.

Source: http://www.ssa.gov/policy/docs/policybriefs/pb2011-02.html

One group of politicos claims the rich are paying all the taxes, and the other group of politicos claim they will 'soak the rich' to take the tax burden off the middle-class.

They sing their soap operas, but they both known damn well where the finish line is in regards to funding the Government. It is on the backs of the middle-class.

"Look, if you let us raise your tax rates a little bit, we are going to 'really soak' this tiny handful of people who don't care anyway."

You can bookmark this post, I promise you that when the government removes the cap on SS, it will come with a "modest" FICA tax increase.

That anyone, anywhere believes that "The Rich" pay the majority of taxes, or even can pay the majority of taxes, is an indication only of the math illiteracy of the people who believe that.