One threatening letter to Wisconsin Gov. Scott Walker promised to attack his wife and "gut her like a deer." Another talked about killing his sons: "I already follow them when they went to school." Then there was the time the governor's car was attacked by protesters who, as Walker recounts in his book, "surrounded the car and began beating on the windows and rocking the vehicle." The Badger State executive withstood an occupation of his state capitol, pickets outside his home, and a recall campaign. All of this was in response to his 2011 budget bill that required public workers to make increased contributions toward their pensions and health insurance. The bill also cut back collective bargaining rights for public employee unions. As a profile in courage for our time, writes Ira Stoll, Gov. Walker turns out to be a pretty good example.