You can make the same argument about the income tax and similarly limit the taxable income from it which will lead to the tax revenue being cut approximately in half.

Also, after Congress raided the Social Security account, they made the point that Social Security is just another tax subject to spending in the general budget.

If that's the case, there are as many arguments for capping/uncapping the FICA taxes as for all other taxes. The problem with such arguments is their appeal to a notion of fairness which has as many faces as economics theories out there - basically a dead end - courtesy of our not-so-diligent economics "science".

So, it's better to use the achievement of better economic, political and social results as the only guidance for fiscal policy, although that requires a level of analysis which far exceeds what mainstream economics has to offer.

Could you please expand on this: "after Congress raided the Social Security account..."? What do you mean by that? AFAIK, Social Security contributions stay within the Social Security Fund - they cannot be used by US government to pay its bills.

> Could you please expand on this: "after Congress raided the Social Security account..."?

I'd ask you, and others reading my previous comment, to scratch this off as a bad choice of words on my part and replace it with:

"by moving to a pay-as-you-go policy for the SSTF, Congress made the point that Social Security is just another tax."

Previously I used "raiding" as a far-fetched metaphor for several different processes which are too complex to discuss here and it would distract from the main point: instead of complex itemization, SSFT & MCFT would be better off as parts of general taxation.

> AFAIK, Social Security contributions stay within the Social Security Fund - they cannot be used by US government to pay its bills.

True in theory, but if we look at how surpluses are handled and how they depend on a manually controlled interest rate we'll see a different reality.