The other day, John McCain offered a zinger about Barack Obama:

One of his favorite phrases is that I would be a Bush third term. Well I think maybe his proposals could be Carter’s second term.

Some in the blogosphere have been cackling about this line. Doesn’t McCain know that the Carter presidency was 28 years ago? Who remembers it? Why would young people care? In an item called “Lame,” Joe Klein writes:

 John McCain quipped yesterday that Barack Obama is “running for Jimmy Carter’s second term.” I can’t imagine that most people under the age of 40 are old enough to remember what Carter’s first term was like. It was done 28 years ago. For my kids, it’s as vivid as Calvin Coolidge’s first term. Of course, I remember Carter’s sad presidency as if it were only yesterday…and I imagine McCain does, too. Can’t remember where I left the car keys, though.

Get it? McCain is old. Funny. The thing is, America is old too. Every ten years the census measures the median age of the United States. Since 1970, the median age has risen from 28 to 35.  (Between 1990 and 2000, the number of Americans between the ages of 35 and 64 grew by 28 percent, while the number of Americans between the ages of 18 and 34 dropped by 4 percentage points.) The next census will surely measure a percentage gain of older Americans as well, largely due to improvements in medicine that are keeping people alive decades longer than before.

What this means is simple: There are twice as many potential American voters who do remember the late 1970s than there are potential American voters who do not. I don’t think McCain should harp on the potential comparisons between Obama and Jimmy Carter, but the notion that the country is just so gloriously young, young, young that it has no recall of those days is simply demographically incorrect. Not to mention that every voter survey since 1972 makes clear that the older you are, the more likely it is that you will vote…