At the time of writing, President Obama’s hoped-for “Grand Bargain” with Republicans is apparently dead. And I say good riddance. I’m no more eager than other rational people (a category that fails to include many Congressional Republicans) to see what happens if the debt limit isn’t raised. But what the president was offering to the G.O.P., especially on Medicare, was a very bad deal for America.

Specifically, according to many reports, the president offered both means-testing of Medicare benefits and a rise in the age of Medicare eligibility. The first would be bad policy; the second would be terrible policy. And it would almost surely be terrible politics, too.

The crucial thing to remember, when we talk about Medicare, is that our goal isn’t, or at least shouldn’t be, defined in terms of some arbitrary number. Our goal should be, instead, to give Americans the health care they need at a price the country can afford. And throwing Americans in their mid-60s off Medicare moves us away from that goal, not toward it.

For Medicare, with all its flaws, works better than private insurance. It has less bureaucracy and, hence, lower administrative costs than private insurers. It has been more successful in controlling costs. While Medicare expenses per beneficiary have soared over the past 40 years, they’ve risen significantly less than private insurance premiums. And since Medicare-type systems in other advanced countries have much lower costs than the uniquely privatized U.S. system, there’s good reason to believe that Medicare reform can do a lot to control costs in the future.