Henry Aaron - not Hammerin' Hank, but the Brookings Institution economist -- makes it so clear even a Republican could understand it. Whatever savings may be available from making Medicare and Medicaid more efficient, or squeezing providers and beneficiaries, aren't going to cut it:
Whichever approach is followed — repeated modest reductions or a single huge one — if all cuts come exclusively from spending, it will be impossible to sustain anything approximating current commitments under Medicare and Medicaid (and under Social Security) as we know them. Resistance to defense cuts, beyond those already included in the legislation to boost the debt ceiling, is already hardening. A concern about undermining the nation's capacity to meet its international obligations may prevent the repeated allocation of half of spending cuts to national defense. Interest spending will inevitably grow sharply as today's recession-induced, near-zero real interest rates return to normal levels. Outlays other than those for defense, interest, Medicare, Medicaid, and Social Security today constitute only one third of the budget and have been cut deeply already. Following the Willie Sutton principle, Congress would have to “go where the money is” and slash the major social insurance programs, including Medicaid and Medicare.
To avoid this outcome, tax increases must account for a sizable fraction — perhaps most — of any deficit-reduction plan.
That's it. If we want to keep the promise made long ago that elderly people will not have to fear dying uncared for in the cold and dark, the Koch brothers will have to pay more taxes. There's no way around it. That's the cold truth.