So, here's the definition of libel.
This is the important fact: The statement(s) alleged to be defamatory must also be a false statement of fact. That which is name-calling, hyperbole, or, however characterized, cannot be proven true or false, cannot be the subject of a libel or slander claim.
Leopold lies. He has no credibility. We only read articles written about him. He's made himself a public figure. No legs to stand on. Seriously, get over it already.