Of all the appalling tidbits that leaked out of the various closed-door debt-ceiling negotiations of the past few months, one of the most stunning items was the news that Obama had proposed raising the Medicare eligibility age from sixty-five to sixty-seven. Not only did he propose it — he was really hoping it would happen. This provoked a collective wail of despair from a number of bloggers and commentators. Paul Krugman wrote a whole column about it.

Most of the responses to the news focused on how bad the policy is. But the more interesting question is why Obama wanted to push it in the first place. Yesterday, Ezra Klein had a post titled “Why the Obama administration is open to raising the Medicare age.” There are few commentators as well informed on policy and as well connected and sympathetic to the Obama administration, so when Klein speaks on this topic, we should listen. Here’s his take, based, it appears, on his own reporting:

I would infer that this is exactly what it looks like: The White House’s political strategy right now is to show that they’re willing to make tough compromises and the other side isn’t. The problem is, how do you prove that you’re willing to make tough compromises? The Medicare eligibility age is, or was, the answer to that problem.

When voters hear that you’re open to cutting $1.2 trillion from discretionary spending, do they realize that’s a tough compromise? What about cutting $200 billion from mandatory spending? Or changing the rate of inflation in Social Security? Most of these policy proposals are completely opaque to normal human beings. They have no idea what they mean in terms of programs, much less on some abstract spectrum labeled “compromise.” Raising the Medicare eligibility age, in contrast, is a clear concession. It carries enormous symbolic weight for Democrats. It provokes screams from the left.