A whopping 79% of federal spending consists of transfer payments, mostly Social Security, Medicare, and Medicaid. When taken in aggregate health care spending is by far the largest part of the federal budget. Health care spending can’t be cut without a) cutting the reimbursements paid to providers; b) not paying for the health care that somebody wants or needs; or c) both.
That would evoke howls of anguish from providers, beneficiaries of federal health care spending programs, the well-intentioned, and the politically opportunistic.
And that’s why we can’t cut federal spending. The same argument applies to the second largest chunk, Social Security. The howls would just be coming from a slightly narrower (but overlapping) slice of the population. It is now true that if defense spending were cut to zero, it would not balance the budget. And we’re increasing defense spending.