"She's there to, that terrifying phrase, cleanse this place," says Staunton. "Her goal is to make things orderly and clean, everyone thinking like she's thinking, that terrifying Nazi-type behavior. She doesn't even like children." (Yates equates her to Oliver North. "He went under the radar and did the dirty stuff because he knew that's what the administration wanted," he notes. "Umbridge is doing the same thing. She's getting rid of Harry Potter because the ministry would really like that.")

"Having seen 'Vera Drake,' I thought, 'How on Earth is she going to come across as anything but the nicest woman in the world?' " remembers Emma Watson, who plays Hermione Granger in the "Harry Potter" movies. "But she's perfect. There's something very distressing about Umbridge, probably because she has the classic appearance of some sort of aunt. But she is this very cruel … person."

"It was horrible," says Staunton, who'd worked with Radcliffe previously on a BBC production of "David Copperfield." "I was fine at the time, but afterward, you're inside that skin for a while, and it's not a very pleasant place to be. It's an adult abusing a child, and whether you're a mother or not, for a female to do it to a child is unthinkable and unbearable and intolerable."