I have no idea what that sentance means, but the facts are wrong. Here's a photo of JFK at his inauguration. As you can see, his head is covered. More from snopes:
It is true that Kennedy almost never wore a hat after becoming president, but his hatlessness was much more likely the continuation of a trend that had long since begun, not its origin. Either way, the common claim that the shunning of hats by American men began because Kennedy declined to wear one to his inauguration is flat-out wrong.The rest of Pinchos's post is so stupid it could trip over a cordless phone. Perhaps a fisking tomorrow if I have the strength.
[Hat tip Al Gore]