It was among the juicier post-election recriminations: Fox News Channel quoted an unnamed McCain campaign figure as saying that Sarah Palin did not know that Africa was a continent. Turns out it was Martin Eisenstadt, a McCain policy adviser, who has come forward today to identify himself as the source of the leaks. Trouble is, Martin Eisenstadt doesn’t exist. His blog does, but it’s a put-on. And the claim of credit for the Africa anecdote is just the latest ruse by Eisenstadt, who turns out to be a very elaborate hoax that has been going on for months.