Darcy Burner knew that prospective Democratic candidates sometimes left in tears after meeting Representative Rahm Emanuel of Chicago, who heads the party's efforts to recapture the House and was the one-man screening committee for recruits. Burner, an alumna of Harvard and Microsoft, didn't cry. But she found the wiry former Clinton Administration official as ruthless as any corporate chieftain she had known, as he went down a checklist of questions, including one at the top he had written to himself: Is she worth the investment of my time and the committee's money?
"Apparently, it didn't occur to him that I could read...