No one — not the bullpen of the New York Mets, not the French army, not Wile E. Coyote, not even Al Gore — is better at squandering a commanding lead than the Queen of Coasting, Hillary Rodham Clinton. And nobody is better at handing her adversaries talking points to undermine trust, on emails, on the Clinton Foundation, on her own refusal to do something as simple as talking to the reporters who cover her every day.