Bad political movements provide easy answers in the form of all-encompassing worldviews: it's the demons, or the Joos, or the filthy Arabs, or the dirty Mexicans, or the capitalist swine, or Jane Fonda. (Or all of them working together.) Cast them out and all your problems will vanish.
By contrast, good political movements cannot provide easy answers, or in most cases any answers at all. What we think we can do is get us all $4 an hour more, plus health care and a little more control over our lives. What we can't do is end human suffering.