FICA--social security and medicare payroll tax-- is regressive, and that's what is causing its perceived shortfall. As income disparity grows, FICA gets less income. The math is very simple--so simple, even a Republican should understand this while he/she is drinking tea.
This is actually not worthy of explaining, and I wouldn't, if only Democrats refuted Republican bullshit. The cap on ss withholding is now $106,800--and the maximum that can be withheld from an individual is $6,621.60. Thus, a person making $106k pays the same dollar amount as the person making $200k, as the person making $2 million, as the person making $2 billion. The employer matches the ss 6.2% for the same limit--thus social security trust fund collects 14.4% of the cap amount.
Now, if we agree incomes have become less equal recently, we should understand the problem. For example--XYZ has a payroll of $200,000,000-- with nobody making above $106,800--SS collects $28,800,000. Same payroll with 5 execs making a total of $100,000,000 and the rest split to employees none making above the limit. Result--top 5 generate $66,218--bottom generate $14,400,000--totaling $14,466,218. FICA is short $14,333,782.
Now please check my math--I have to leave now--and send this along to your local Dem to use as a talking point. Truth to lies works--compromise to lies destroys.