Tim Walz has such a bad record as Minnesota’s governor that I was astonished when he landed on Vice President Kamala Harris’s vice-presidential shortlist. As Minnesota’s Center of the American Experiment has documented, under Mr. Walz Minnesota has become a high-crime state. Student achievement has tumbled as spending on schools has skyrocketed. Per capita gross domestic product has fallen below the national average. Minnesotans have joined residents of New York, California and Illinois in fleeing their home state.