It turns out that if you strike the Medicare plan from the GOP budget—authored by Rep. Paul Ryan (R-WI)—it doesn't achieve fiscal balance anymore.

"It certainly blows a major hole in his plan," said Paul Van de Water, a health care and budget expert at the Center on Budget and Policy Priorities, in a phone interview.

If you take Ryan at his word, and assume that the tax-side of his plan is revenue neutral—a big "if"—his plan balances the budget over decades entirely on the spending side of the government's ledger. Van de Water explains that if you take the Medicare privatization plan out of the equation, the budget sinks—dragged down by higher spending, and then higher interest payments as a result of larger-than-projected deficits.

"That plus interest gets you into a range where you no longer balance the budget," Van de Water said.