A sapient (it seems to me) sociological observation from a reader, following my comment on Obama’s lightness:

Mr. Derbyshire — Yes, Obama is incredibly light, but he (and his wife) are the perfect representation of most of today’s elite world. First you get born with a good IQ to upper middle class parents. Then you get insulated in all the right schools … You take a year or two off after that Ivy or near-Ivy school to build your “not sell out” credentials. Then you use your school contacts and any of your parents’ contacts to get a career. Since you are clearly an up and comer, you spend half your time looking for the next promotion which someone always gives you. You just make sure it is in a no-risk position where it doesn’t really matter what you do because the decisions have been made, or there are no real decisions. If you get yourself into a spot where you need to make real decisions, you spend all your time looking for the next promotion and get out of Dodge before something sticks.
By the time you are forty, you have a career path with apparently increasing responsibility, yet have never made a real decision in your life. You’ve even outsourced the raising of you one child to the Mexican nanny. And worst of all, all the people in those positions think they have lots a valuable life experience. (I guarantee Obama thinks so.) The only thing that separates Obama is his incredibly messed up childhood. Complaining about Obama’s lightness won’t resonate, because most of the American elite have the same track record.
Life has been very good in this country for a very long time. Finding an elite (even an FDR who lived through polio) with character is a tough proposition. The GOP had to take a 71-year-old.

Point taken, though I’m not sure that “upper middle class” is a fair description of Michelle’s parents.

Still, there are degrees of lightness even among our current cognitive elites. There are c.e.s who made Eagle Scout, or did dirty jobs in college vacations, or formed a successful rock group, or swam the Bosphorus.

Several readers have pointed out that John Edwards is even lighter in weight than Obama. True enough — I think John’s handlers must keep him tethered to stop him floating off into the sky. Still, he was never his party’s presumptive nominee. Other names mentioned unflatteringly by readers in this context include Dan Quayle, Bill Clinton, and, er, George W. Bush. Well, being Governor of Arkansas or Texas isn’t nothing, executive-wise; and Dan … plays a pretty good game of golf.