ANOTHER DAY, another trial balloon to launch over the "fiscal cliff." In exchange for Republicans' agreeing to allow tax rates on the wealthiest 2 percent of Americans to rise a few percentage points, President Obama reportedly is entertaining the idea of raising the Medicare eligibility age from 65 to 67. Again. (He reportedly was willing to make this concession during the debt-ceiling crisis in 2011.)

Trial balloons are proposals that are floated publicly to gauge political and public reaction, and the negative response to this one should be swift and sharp enough to shred it.

It's true that the rising costs to government for Medicare and Medicaid are a major reason that the federal budget deficit is projected to rise in the future. But the answer is not to cut the programs, it's to cut health-care costs that are going up for everyone. And privatizing Medicare for this group of older adults would do the exact opposite.

According to the Kaiser Family Foundation, the move would save $5.7 billion from the federal budget in the first year following full enactment, but that's only because the individual seniors, their employers and states dealing with more Medicaid recipients would be footing the bill. And the bill would be much higher - double, in fact, at $11.4 billion.

Medicare already costs much less to recipients than private health insurance: Its risk pool is so large, it can negotiate lower prices from health-care providers, and its administrative costs are quite low.

Uninsured seniors not covered by their employers would turn to the Affordable Care Act's health-insurance exchanges (possibly receiving government subsidies). But by adding people who statistically have the most medical problems, insurance rates for everyone in the private-risk pool will go up. And by bumping the youngest, statistically healthiest recipients from Medicare, those premiums can also be expected to rise (by 3 percent.) Everybody loses.

And the Center for American Progress reported Wednesday that if states opt out of expanding Medicaid as part of ACA - which Pennsylvania Gov. Corbett says he will do - that could leave a potential 435,000 low-income seniors with no health-insurance options at all.

The idea of cutting Medicare benefits is highly unpopular, according to the polls.

So why is the idea back on the table at all? As a "trophy," as House Minority Leader Nancy Pelosi has put it, for Republican leaders to display to their base. The issue has a "weirdly disproportionate symbolic power" among Republicans, writes Jonathan Chait of New York magazine, not to mention the inside-the-Beltway "serious people" who want so much for everyone to "share" the pain that they won't ever have to feel.

So there you have it: a bad public policy that will hurt the economy, one that most Americans don't want, but still may get because their so-called representatives (and the mainstream media) need a symbolic win.

There's no better time for ordinary Americans to make clear that the this kind of game-playing with people's lives can't go on. Puncture this trial balloon now.