Congressional Budget Office Director Douglas Elmendorf addresses a National Economists Club luncheon in February. (By Alex Wong/Getty Images)

Back during the health-care reform fight, the Congressional Budget Office looked at the likely effect of adding a public option that paid Medicare rates. “In total, a public plan based on Medicare rates would save $110 billion over 10 years,” the agency concluded. Importantly, the savings would come because premiums would be lower. The basic mechanism here is not complicated: Just as you get better deals by shopping at a mega-retailer like Wal-Mart, you get better deals by working with a mega-insurer like Medicare. Size matters.

As for Ryan’s plan, CBO’s take was just the opposite. “Under the proposal,” they said, “most elderly people would pay more for their health care than they would pay under the current Medicare system.” That is to say, health-care costs go up. Now, federal health-care spending goes down, as seniors are paying 70 percent of their costs out-of-pocket rather than 30 percent. Or, in CBO-ese, Medicare beneficiaries “would bear a much larger share of their health care costs than they would under the current program.” Of course, back in the real world, seniors are going to react poorly to being unable to afford health-care insurance, and those savings won’t manifest.

But even putting that aside, it makes for a very stark contrast. The progressive reform that won’t happen would cut health-care costs. The conservative reform that won’t happen would increase health-care costs. One idea makes insurance cheaper and one makes it more expensive. And yet the idea that makes insurance cheaper is pretty much off the table, while the idea that makes it more expensive — and that almost certainly wouldn’t work — is considered a very serious proposal worthy of brow-furrowing debate.