There is evil in the world. In fact, there are too many examples, from Jerry Sandusky and Ariel Castro in the United States to Assad gassing civilians in Syria to Islamic terrorists killing shoppers in a Nairobi mall. You could make a list of all the evil in the world and run out of ideas before you would ever think of writing down the name of Diane Ravitch, a grandmother who has dedicated her life to protecting public schools, but don’t tell that to Rep. Jared Polis, a Colorado Democrat.On Thursday, Sep. 19, Randi Weingarten, president of the American Federation of Teachers, tweeted out a link to a good review of Ravitch’s latest book, “Reign of Error: The Hoax of the Privatization Movement and the Danger to America’s Public Schools.”