Carly Fiorina is the new "it" candidate in the Republican presidential field, following a second straight sterling debate performance at the Ronald Reagan presidential library Wednesday night. But there was a moment in the debate that previewed a major potential weakness for Fiorina. It came when moderator Jake Tapper noted that Donald Trump had said Fiorina "ran HP into the ground" during her time as CEO. Fiorina responded, "I led Hewlett Packard through a very difficult time, the worst technology recession in 25 years," adding: "We had to make tough choices, and in doing so, we saved 80,000 jobs, went...