No joke: Hillary Clinton's laugh is now being analyzed, scrutinized and, yes, mocked as if it were a sound barrier on her glide path to the Democratic presidential nomination: Is it real? Is it fake? Is it a diabolically clever attempt to portray her as a human being?

What a hoot.

Jon Stewart, setting the pace for political journalism, kicked things off last week by assembling a grab bag of giggling and guffawing when the...