Charles Munger, vice chairman of Berkshire Hathaway, the other day described Silicon Valley billionaire Elon Musk as a "genius." Maybe he was alluding to the Tesla CEO's cunning ploy to mine subsidies from Nevada taxpayers.

Last week the Silver State's legislature unanimously approved $1.3 billion in tax breaks for Tesla to build a $5 billion lithium battery factory in Reno that will supply its electric-car plant in Fremont, California. "We have changed the trajectory of this state, perhaps forever," declared...